* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
[not found] <CAGNvRgCv1Y8a6DGO=p9g8FAve1-UKf53vshqFYtdmWkDUzn8+Q@mail.gmail.com>
@ 2017-07-28 20:26 ` Tim Song
2017-07-28 20:29 ` Daniel Krügler
0 siblings, 1 reply; 12+ messages in thread
From: Tim Song @ 2017-07-28 20:26 UTC (permalink / raw)
To: Daniel Krügler; +Cc: libstdc++, gcc-patches
On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
<daniel.kruegler@gmail.com> wrote:
> + // Performs an implicit conversion from _Tp to __sv_type.
> + template<typename _Tp>
> + static __sv_type _S_to_string_view(const _Tp& __svt)
> + {
> + return __svt;
> + }
I might have gone for
+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
+ {
+ return __svt;
+ }
With that, we can also use noexcept(_S_to_string_view(__t)) to make up
for the absence of is_nothrow_convertible (basically the same thing I
did in LWG 2993's PR).
Tim
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-07-28 20:26 ` [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946) Tim Song
@ 2017-07-28 20:29 ` Daniel Krügler
2017-07-28 20:40 ` Daniel Krügler
0 siblings, 1 reply; 12+ messages in thread
From: Daniel Krügler @ 2017-07-28 20:29 UTC (permalink / raw)
To: Tim Song; +Cc: libstdc++, gcc-patches
2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
> <daniel.kruegler@gmail.com> wrote:
>> + // Performs an implicit conversion from _Tp to __sv_type.
>> + template<typename _Tp>
>> + static __sv_type _S_to_string_view(const _Tp& __svt)
>> + {
>> + return __svt;
>> + }
>
> I might have gone for
>
> + static __sv_type _S_to_string_view(__sv_type __svt) noexcept
> + {
> + return __svt;
> + }
>
> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
> for the absence of is_nothrow_convertible (basically the same thing I
> did in LWG 2993's PR).
Agreed, that makes very much sense. I will adjust the P/R, but before
I resubmit I would like to get feedback whether the other two compare
functions also should become conditionally noexcept.
Thanks,
- Daniel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-07-28 20:29 ` Daniel Krügler
@ 2017-07-28 20:40 ` Daniel Krügler
2017-07-30 13:01 ` Daniel Krügler
0 siblings, 1 reply; 12+ messages in thread
From: Daniel Krügler @ 2017-07-28 20:40 UTC (permalink / raw)
To: Tim Song; +Cc: libstdc++, gcc-patches
2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
> 2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>> <daniel.kruegler@gmail.com> wrote:
>>> + // Performs an implicit conversion from _Tp to __sv_type.
>>> + template<typename _Tp>
>>> + static __sv_type _S_to_string_view(const _Tp& __svt)
>>> + {
>>> + return __svt;
>>> + }
>>
>> I might have gone for
>>
>> + static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>> + {
>> + return __svt;
>> + }
>>
>> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>> for the absence of is_nothrow_convertible (basically the same thing I
>> did in LWG 2993's PR).
>
> Agreed, that makes very much sense. I will adjust the P/R, but before
> I resubmit I would like to get feedback whether the other two compare
> functions also should become conditionally noexcept.
Locally I have now performed the sole change of the _S_to_string_view
declaration getting rid of the template, but would also like to gather
feedback from the maintainers whether I should also change the form of
the conditional noexcept to use the expression
noexcept(_S_to_string_view(__t))
instead of the current
is_same<_Tp, __sv_type>::value
as suggested by Tim Song.
I'm asking also, because I have a paper proposing to standardize
is_nothrow_convertible submitted for the upcoming C++ mailing - This
would be one of the first applications in the library ;-)
> Thanks,
>
> - Daniel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-07-28 20:40 ` Daniel Krügler
@ 2017-07-30 13:01 ` Daniel Krügler
2017-08-18 18:27 ` Daniel Krügler
2017-09-04 15:48 ` Jonathan Wakely
0 siblings, 2 replies; 12+ messages in thread
From: Daniel Krügler @ 2017-07-30 13:01 UTC (permalink / raw)
To: Tim Song; +Cc: libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 2166 bytes --]
2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
> 2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>> 2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>> <daniel.kruegler@gmail.com> wrote:
>>>> + // Performs an implicit conversion from _Tp to __sv_type.
>>>> + template<typename _Tp>
>>>> + static __sv_type _S_to_string_view(const _Tp& __svt)
>>>> + {
>>>> + return __svt;
>>>> + }
>>>
>>> I might have gone for
>>>
>>> + static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>> + {
>>> + return __svt;
>>> + }
>>>
>>> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>> for the absence of is_nothrow_convertible (basically the same thing I
>>> did in LWG 2993's PR).
>>
>> Agreed, that makes very much sense. I will adjust the P/R, but before
>> I resubmit I would like to get feedback whether the other two compare
>> functions also should become conditionally noexcept.
>
> Locally I have now performed the sole change of the _S_to_string_view
> declaration getting rid of the template, but would also like to gather
> feedback from the maintainers whether I should also change the form of
> the conditional noexcept to use the expression
>
> noexcept(_S_to_string_view(__t))
>
> instead of the current
>
> is_same<_Tp, __sv_type>::value
>
> as suggested by Tim Song.
>
> I'm asking also, because I have a paper proposing to standardize
> is_nothrow_convertible submitted for the upcoming C++ mailing - This
> would be one of the first applications in the library ;-)
A slightly revised patch update: It replaces the _S_to_string_view
template by a simpler _S_to_string_view function as of Tim Song's
suggestion, but still uses the simplified noexcept specification
deferring it to a future application case for is_nothrow_convertible.
Furthermore now all three compare function templates are now
(conditionally) noexcept by an (off-list) suggestion from Jonathan
Wakely.
Thanks,
- Daniel
[-- Attachment #2: ChangeLog_79162.patch --]
[-- Type: application/octet-stream, Size: 2161 bytes --]
Index: libstdc++-v3/ChangeLog
===================================================================
--- libstdc++-v3/ChangeLog (revision 250720)
+++ libstdc++-v3/ChangeLog (working copy)
@@ -1,3 +1,34 @@
+2017-07-30 Daniel Kruegler <daniel.kruegler@gmail.com>
+
+ PR libstdc++/79162
+ Implement LWG 2946, LWG 2758's resolution missed further corrections
+ * include/bits/basic_string.h (basic_string::compare): Add missing
+ required noexcept specifications.
+ * include/bits/basic_string.h (basic_string): Introduce internal
+ _S_to_string_view and __sv_wrapper for implicit string_view conversion.
+ * include/bits/basic_string.h (basic_string::basic_string): Fix explicit
+ string_view conversion by implicit conversion using _S_to_string_view and
+ __sv_wrapper.
+ * include/bits/basic_string.h (basic_string): Introduce internal
+ basic_string(__sv_wrapper, Alloc) constructor.
+ * include/bits/basic_string.h (basic_string): Fix operator=(T) template
+ by operator=(const T&) template for uncopyable types (79162).
+ * include/bits/basic_string.h (basic_string::operator+=,
+ basic_string::append, basic_string::assign, basic_string::insert,
+ basic_string::replace, basic_string::find, basic_string::rfind,
+ basic_string::find_first_of, basic_string::find_last_of,
+ basic_string::find_first_not_of, basic_string::find_last_not_of,
+ basic_string::compare): Replace __sv_type argument by template const T&
+ (LWG 2946) and correct documentation describing __sv_type argument.
+ * include/bits/basic_string.h (basic_string::find, basic_string::rfind,
+ basic_string::find_first_of, basic_string::find_last_of,
+ basic_string::find_first_not_of, basic_string::find_last_not_of,
+ basic_string::compare): Replace unconditional noexcept specification by
+ conditional noexcept specification to partially balance the remove of
+ noexcept by LWG 2946.
+ * testsuite/21_strings/basic_string/79162.cc: New.
+ * testsuite/21_strings/basic_string/lwg2946.cc: New.
+
2017-07-26 Jonathan Wakely <jwakely@redhat.com>
* testsuite/27_io/basic_fstream/53984.cc: Fix test.
[-- Attachment #3: 79162.patch --]
[-- Type: application/octet-stream, Size: 43088 bytes --]
Index: libstdc++-v3/include/bits/basic_string.h
===================================================================
--- libstdc++-v3/include/bits/basic_string.h (revision 250720)
+++ libstdc++-v3/include/bits/basic_string.h (working copy)
@@ -117,6 +117,22 @@
__and_<is_convertible<const _Tp&, __sv_type>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
+
+ // Allows an implicit conversion to __sv_type.
+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
+ {
+ return __svt;
+ }
+
+ // Wraps a string_view by explicit conversion and thus
+ // allows to add an internal constructor that does not
+ // participate in overload resolution when a string_view
+ // is provided.
+ struct __sv_wrapper
+ {
+ explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) {}
+ __sv_type _M_sv;
+ };
#endif
// Use empty-base optimization: http://www.cantrip.org/emptyopt.html
@@ -593,7 +609,7 @@
#if __cplusplus > 201402L
/**
* @brief Construct string from a substring of a string_view.
- * @param __t Source string view.
+ * @param __t Source object convertible to string view.
* @param __pos The index of the first character to copy from __t.
* @param __n The number of characters to copy from __t.
* @param __a Allocator to use.
@@ -601,16 +617,27 @@
template<typename _Tp, typename = _If_sv<_Tp, void>>
basic_string(const _Tp& __t, size_type __pos, size_type __n,
const _Alloc& __a = _Alloc())
- : basic_string(__sv_type(__t).substr(__pos, __n), __a) { }
-
+ : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
+
/**
* @brief Construct string from a string_view.
- * @param __sv Source string view.
+ * @param __t Source object convertible to string view.
* @param __a Allocator to use (default is default allocator).
*/
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
explicit
- basic_string(__sv_type __sv, const _Alloc& __a = _Alloc())
- : basic_string(__sv.data(), __sv.size(), __a) { }
+ basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
+ : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
+
+ /**
+ * @brief Only internally used: Construct string from a string view
+ * wrapper.
+ * @param __svw string view wrapper.
+ * @param __a Allocator to use.
+ */
+ explicit
+ basic_string(__sv_wrapper __svw, const _Alloc& __a)
+ : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
#endif // C++17
/**
@@ -756,12 +783,12 @@
#if __cplusplus > 201402L
/**
* @brief Set value to string constructed from a string_view.
- * @param __sv A string_view.
+ * @param __svt An object convertible to string_view.
*/
- template<typename _Tp>
- _If_sv<_Tp, basic_string&>
- operator=(_Tp __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(const _Tp& __svt)
+ { return this->assign(__svt); }
/**
* @brief Convert to a string_view.
@@ -1157,12 +1184,13 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt An object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- operator+=(__sv_type __sv)
- { return this->append(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator+=(const _Tp& __svt)
+ { return this->append(__svt); }
#endif // C++17
/**
@@ -1265,29 +1293,33 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt An object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- append(__sv_type __sv)
- { return this->append(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->append(__sv.data(), __sv.size());
+ }
/**
* @brief Append a range of characters from a string_view.
- * @param __sv The string_view to be appended from.
+ * @param __svt An object convertible to string_view to be appended from.
* @param __pos The position in the string_view to append from.
* @param __n The number of characters to append from the string_view.
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- append(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return _M_append(__sv.data()
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return _M_append(__sv.data()
+ __sv._M_check(__pos, "basic_string::append"),
__sv._M_limit(__pos, __n));
- }
+ }
#endif // C++17
/**
@@ -1433,29 +1465,33 @@
#if __cplusplus > 201402L
/**
* @brief Set value from a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @return Reference to this string.
*/
- basic_string&
- assign(__sv_type __sv)
- { return this->assign(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->assign(__sv.data(), __sv.size());
+ }
/**
* @brief Set value from a range of characters in a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @param __pos The position in the string_view to assign from.
* @param __n The number of characters to assign.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return _M_replace(size_type(0), this->size(), __sv.data()
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return _M_replace(size_type(0), this->size(), __sv.data()
+ __sv._M_check(__pos, "basic_string::assign"),
__sv._M_limit(__pos, __n));
- }
+ }
#endif // C++17
#if __cplusplus >= 201103L
@@ -1692,32 +1728,36 @@
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- insert(size_type __pos, __sv_type __sv)
- { return this->insert(__pos, __sv.data(), __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->insert(__pos, __sv.data(), __sv.size());
+ }
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos Iterator referencing position in string_view to insert
* from.
* @param __n The number of characters to insert.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- insert(size_type __pos1, const _Tp& __svt,
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos1, const _Tp& __svt,
size_type __pos2, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, size_type(0), __sv.data()
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, size_type(0), __sv.data()
+ __sv._M_check(__pos2, "basic_string::insert"),
__sv._M_limit(__pos2, __n));
- }
+ }
#endif // C++17
/**
@@ -2120,32 +2160,36 @@
* @brief Replace range of characters with string_view.
* @param __pos The position to replace at.
* @param __n The number of characters to replace.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- replace(size_type __pos, size_type __n, __sv_type __sv)
- { return this->replace(__pos, __n, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos, size_type __n, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos, __n, __sv.data(), __sv.size());
+ }
/**
* @brief Replace range of characters with string_view.
* @param __pos1 The position to replace at.
* @param __n1 The number of characters to replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos2 The position in the string_view to insert from.
* @param __n2 The number of characters to insert.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- replace(size_type __pos1, size_type __n1, const _Tp& __svt,
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos1, size_type __n1, const _Tp& __svt,
size_type __pos2, size_type __n2 = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, __n1, __sv.data()
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, __n1, __sv.data()
+ __sv._M_check(__pos2, "basic_string::replace"),
__sv._M_limit(__pos2, __n2));
- }
+ }
/**
* @brief Replace range of characters with string_view.
@@ -2153,12 +2197,16 @@
to replace at.
* @param __i2 An iterator referencing the end position
for the replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @return Reference to this string.
*/
- basic_string&
- replace(const_iterator __i1, const_iterator __i2, __sv_type __sv)
- { return this->replace(__i1 - begin(), __i2 - __i1, __sv); }
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__i1 - begin(), __i2 - __i1, __sv);
+ }
#endif // C++17
private:
@@ -2288,13 +2336,18 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of start of first occurrence.
*/
- size_type
- find(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2345,13 +2398,18 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of start of last occurrence.
*/
- size_type
- rfind(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->rfind(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ rfind(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->rfind(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2419,13 +2477,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character of a string_view.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2497,13 +2561,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character of string.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2574,13 +2644,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt A object convertible to string_view containing characters
+ * to avoid.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_not_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_not_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2650,13 +2726,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_not_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_not_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2754,12 +2836,14 @@
#if __cplusplus > 201402L
/**
* @brief Compare to a string_view.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(__sv_type __sv) const
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(const _Tp& __svt) const noexcept(is_same<_Tp, __sv_type>::value)
{
+ __sv_type __sv = __svt;
const size_type __size = this->size();
const size_type __osize = __sv.size();
const size_type __len = std::min(__size, __osize);
@@ -2774,31 +2858,39 @@
* @brief Compare to a string_view.
* @param __pos A position in the string to start comparing from.
* @param __n The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(size_type __pos, size_type __n, __sv_type __sv) const
- { return __sv_type(*this).substr(__pos, __n).compare(__sv); }
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos, size_type __n, const _Tp& __svt) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this).substr(__pos, __n).compare(__sv);
+ }
/**
* @brief Compare to a string_view.
* @param __pos1 A position in the string to start comparing from.
* @param __n1 The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @param __pos2 A position in the string_view to start comparing from.
* @param __n2 The number of characters to compare.
* @return Integer < 0, 0, or > 0.
*/
- template <typename _Tp>
- _If_sv<_Tp, int>
- compare(size_type __pos1, size_type __n1, const _Tp& __svt,
- size_type __pos2, size_type __n2 = npos) const
- {
- __sv_type __sv = __svt;
- return __sv_type(*this)
- .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
- }
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos1, size_type __n1, const _Tp& __svt,
+ size_type __pos2, size_type __n2 = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this)
+ .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
+ }
#endif // C++17
/**
@@ -3348,6 +3440,22 @@
__and_<is_convertible<const _Tp&, __sv_type>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
+
+ // Allows an implicit conversion to __sv_type.
+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
+ {
+ return __svt;
+ }
+
+ // Wraps a string_view by explicit conversion and thus
+ // allows to add an internal constructor that does not
+ // participate in overload resolution when a string_view
+ // is provided.
+ struct __sv_wrapper
+ {
+ explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) {}
+ __sv_type _M_sv;
+ };
#endif
public:
@@ -3474,24 +3582,35 @@
#if __cplusplus > 201402L
/**
* @brief Construct string from a substring of a string_view.
- * @param __t Source string view.
+ * @param __t Source object convertible to string view.
* @param __pos The index of the first character to copy from __t.
* @param __n The number of characters to copy from __t.
* @param __a Allocator to use.
*/
- template<typename _Tp, typename = _If_sv<_Tp, void>>
- basic_string(const _Tp& __t, size_type __pos, size_type __n,
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
+ basic_string(const _Tp& __t, size_type __pos, size_type __n,
const _Alloc& __a = _Alloc())
- : basic_string(__sv_type(__t).substr(__pos, __n), __a) { }
-
+ : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
+
/**
* @brief Construct string from a string_view.
- * @param __sv Source string view.
+ * @param __t Source object convertible to string view.
* @param __a Allocator to use (default is default allocator).
*/
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
explicit
- basic_string(__sv_type __sv, const _Alloc& __a = _Alloc())
- : basic_string(__sv.data(), __sv.size(), __a) { }
+ basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
+ : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
+
+ /**
+ * @brief Only internally used: Construct string from a string view
+ * wrapper.
+ * @param __svw string view wrapper.
+ * @param __a Allocator to use.
+ */
+ explicit
+ basic_string(__sv_wrapper __svw, const _Alloc& __a)
+ : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
#endif // C++17
/**
@@ -3562,12 +3681,12 @@
#if __cplusplus > 201402L
/**
* @brief Set value to string constructed from a string_view.
- * @param __sv A string_view.
+ * @param __svt An object convertible to string_view.
*/
- template<typename _Tp>
- _If_sv<_Tp, basic_string&>
- operator=(_Tp __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(const _Tp& __svt)
+ { return this->assign(__svt); }
/**
* @brief Convert to a string_view.
@@ -3984,12 +4103,13 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt The object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- operator+=(__sv_type __sv)
- { return this->append(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator+=(const _Tp& __svt)
+ { return this->append(__svt); }
#endif // C++17
/**
@@ -4075,29 +4195,34 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt The object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- append(__sv_type __sv)
- { return this->append(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->append(__sv.data(), __sv.size());
+ }
/**
* @brief Append a range of characters from a string_view.
- * @param __sv The string_view to be appended from.
+ * @param __svt The object convertible to string_view to be appended
+ * from.
* @param __pos The position in the string_view to append from.
* @param __n The number of characters to append from the string_view.
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- append(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return append(__sv.data()
- + __sv._M_check(__pos, "basic_string::append"),
- __sv._M_limit(__pos, __n));
- }
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return append(__sv.data()
+ + __sv._M_check(__pos, "basic_string::append"),
+ __sv._M_limit(__pos, __n));
+ }
#endif // C++17
/**
@@ -4228,29 +4353,33 @@
#if __cplusplus > 201402L
/**
* @brief Set value from a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @return Reference to this string.
*/
- basic_string&
- assign(__sv_type __sv)
- { return this->assign(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->assign(__sv.data(), __sv.size());
+ }
/**
* @brief Set value from a range of characters in a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @param __pos The position in the string_view to assign from.
* @param __n The number of characters to assign.
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return assign(__sv.data()
- + __sv._M_check(__pos, "basic_string::assign"),
- __sv._M_limit(__pos, __n));
- }
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return assign(__sv.data()
+ + __sv._M_check(__pos, "basic_string::assign"),
+ __sv._M_limit(__pos, __n));
+ }
#endif // C++17
/**
@@ -4432,17 +4561,21 @@
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- insert(size_type __pos, __sv_type __sv)
- { return this->insert(__pos, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->insert(__pos, __sv.data(), __sv.size());
+ }
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos Iterator referencing position in string_view to insert
* from.
* @param __n The number of characters to insert.
@@ -4449,15 +4582,15 @@
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- insert(size_type __pos1, const _Tp& __svt,
- size_type __pos2, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, size_type(0), __sv.data()
- + __sv._M_check(__pos2, "basic_string::insert"),
- __sv._M_limit(__pos2, __n));
- }
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos1, const _Tp& __svt,
+ size_type __pos2, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, size_type(0), __sv.data()
+ + __sv._M_check(__pos2, "basic_string::insert"),
+ __sv._M_limit(__pos2, __n));
+ }
#endif // C++17
/**
@@ -4819,32 +4952,36 @@
* @brief Replace range of characters with string_view.
* @param __pos The position to replace at.
* @param __n The number of characters to replace.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- replace(size_type __pos, size_type __n, __sv_type __sv)
- { return this->replace(__pos, __n, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos, size_type __n, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos, __n, __sv.data(), __sv.size());
+ }
/**
* @brief Replace range of characters with string_view.
* @param __pos1 The position to replace at.
* @param __n1 The number of characters to replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos2 The position in the string_view to insert from.
* @param __n2 The number of characters to insert.
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- replace(size_type __pos1, size_type __n1, const _Tp& __svt,
- size_type __pos2, size_type __n2 = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, __n1, __sv.data()
- + __sv._M_check(__pos2, "basic_string::replace"),
- __sv._M_limit(__pos2, __n2));
- }
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos1, size_type __n1, const _Tp& __svt,
+ size_type __pos2, size_type __n2 = npos)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, __n1, __sv.data()
+ + __sv._M_check(__pos2, "basic_string::replace"),
+ __sv._M_limit(__pos2, __n2));
+ }
/**
* @brief Replace range of characters with string_view.
@@ -4852,12 +4989,16 @@
to replace at.
* @param __i2 An iterator referencing the end position
for the replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @return Reference to this string.
*/
- basic_string&
- replace(const_iterator __i1, const_iterator __i2, __sv_type __sv)
- { return this->replace(__i1 - begin(), __i2 - __i1, __sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__i1 - begin(), __i2 - __i1, __sv);
+ }
#endif // C++17
private:
@@ -5062,13 +5203,18 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of start of first occurrence.
*/
- size_type
- find(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5135,13 +5281,18 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of start of last occurrence.
*/
- size_type
- rfind(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->rfind(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ rfind(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->rfind(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5213,13 +5364,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character of a string_view.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5291,13 +5448,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character of string.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5366,13 +5529,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_not_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_not_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5442,13 +5611,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_not_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_not_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5498,12 +5673,14 @@
#if __cplusplus > 201402L
/**
* @brief Compare to a string_view.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(__sv_type __sv) const
+ template<typename _Tp>
+ _If_sv<_Tp, int>
+ compare(const _Tp& __svt) const noexcept(is_same<_Tp, __sv_type>::value)
{
+ __sv_type __sv = __svt;
const size_type __size = this->size();
const size_type __osize = __sv.size();
const size_type __len = std::min(__size, __osize);
@@ -5518,31 +5695,39 @@
* @brief Compare to a string_view.
* @param __pos A position in the string to start comparing from.
* @param __n The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(size_type __pos, size_type __n, __sv_type __sv) const
- { return __sv_type(*this).substr(__pos, __n).compare(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos, size_type __n, const _Tp& __svt) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this).substr(__pos, __n).compare(__sv);
+ }
/**
* @brief Compare to a string_view.
* @param __pos1 A position in the string to start comparing from.
* @param __n1 The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @param __pos2 A position in the string_view to start comparing from.
* @param __n2 The number of characters to compare.
* @return Integer < 0, 0, or > 0.
*/
- template <typename _Tp>
- _If_sv<_Tp, int>
- compare(size_type __pos1, size_type __n1, const _Tp& __svt,
- size_type __pos2, size_type __n2 = npos) const
- {
- __sv_type __sv = __svt;
- return __sv_type(*this)
- .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
- }
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos1, size_type __n1, const _Tp& __svt,
+ size_type __pos2, size_type __n2 = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this)
+ .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
+ }
#endif // C++17
/**
Index: libstdc++-v3/testsuite/21_strings/basic_string/79162.cc
===================================================================
--- libstdc++-v3/testsuite/21_strings/basic_string/79162.cc (nonexistent)
+++ libstdc++-v3/testsuite/21_strings/basic_string/79162.cc (working copy)
@@ -0,0 +1,37 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+
+template <class DataType>
+class opt : public DataType
+{
+ opt(const opt &) = delete;
+ opt &operator=(const opt &) = delete;
+public:
+ opt() {}
+};
+
+int main()
+{
+ opt<std::string> PGOTestProfileFile;
+ std::string ProfileFileName;
+ ProfileFileName = PGOTestProfileFile;
+}
Index: libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc
===================================================================
--- libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc (nonexistent)
+++ libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc (working copy)
@@ -0,0 +1,41 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+
+int main()
+{
+ std::string s({"abc", 1});
+ s = {"abc", 1};
+ s += {"abc", 1};
+ s.append({"abc", 1});
+ s.assign({"abc", 1});
+ s.insert(0, {"abc", 1});
+ s.replace(0, 1, {"abc", 1});
+ s.replace(s.cbegin(), s.cbegin(), {"abc", 1});
+ s.find({"abc", 1});
+ s.rfind({"abc", 1});
+ s.find_first_of({"abc", 1});
+ s.find_last_of({"abc", 1});
+ s.find_first_not_of({"abc", 1});
+ s.find_last_not_of({"abc", 1});
+ s.compare({"abc", 1});
+ s.compare(0, 1, {"abc", 1});
+}
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-07-30 13:01 ` Daniel Krügler
@ 2017-08-18 18:27 ` Daniel Krügler
2017-09-04 15:48 ` Jonathan Wakely
1 sibling, 0 replies; 12+ messages in thread
From: Daniel Krügler @ 2017-08-18 18:27 UTC (permalink / raw)
To: Tim Song; +Cc: libstdc++, gcc-patches
Hi,
This is a friendly reminder asking for a review of the suggested patch!
Thanks,
- Daniel
2017-07-30 15:01 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
> 2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>> 2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>> 2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>> <daniel.kruegler@gmail.com> wrote:
>>>>> + // Performs an implicit conversion from _Tp to __sv_type.
>>>>> + template<typename _Tp>
>>>>> + static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>> + {
>>>>> + return __svt;
>>>>> + }
>>>>
>>>> I might have gone for
>>>>
>>>> + static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>> + {
>>>> + return __svt;
>>>> + }
>>>>
>>>> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>> for the absence of is_nothrow_convertible (basically the same thing I
>>>> did in LWG 2993's PR).
>>>
>>> Agreed, that makes very much sense. I will adjust the P/R, but before
>>> I resubmit I would like to get feedback whether the other two compare
>>> functions also should become conditionally noexcept.
>>
>> Locally I have now performed the sole change of the _S_to_string_view
>> declaration getting rid of the template, but would also like to gather
>> feedback from the maintainers whether I should also change the form of
>> the conditional noexcept to use the expression
>>
>> noexcept(_S_to_string_view(__t))
>>
>> instead of the current
>>
>> is_same<_Tp, __sv_type>::value
>>
>> as suggested by Tim Song.
>>
>> I'm asking also, because I have a paper proposing to standardize
>> is_nothrow_convertible submitted for the upcoming C++ mailing - This
>> would be one of the first applications in the library ;-)
>
> A slightly revised patch update: It replaces the _S_to_string_view
> template by a simpler _S_to_string_view function as of Tim Song's
> suggestion, but still uses the simplified noexcept specification
> deferring it to a future application case for is_nothrow_convertible.
> Furthermore now all three compare function templates are now
> (conditionally) noexcept by an (off-list) suggestion from Jonathan
> Wakely.
>
> Thanks,
>
> - Daniel
--
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^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-07-30 13:01 ` Daniel Krügler
2017-08-18 18:27 ` Daniel Krügler
@ 2017-09-04 15:48 ` Jonathan Wakely
2017-09-11 16:55 ` Jonathan Wakely
2017-09-20 15:36 ` Jonathan Wakely
1 sibling, 2 replies; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-04 15:48 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>> 2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>> 2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>> <daniel.kruegler@gmail.com> wrote:
>>>>> + // Performs an implicit conversion from _Tp to __sv_type.
>>>>> + template<typename _Tp>
>>>>> + static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>> + {
>>>>> + return __svt;
>>>>> + }
>>>>
>>>> I might have gone for
>>>>
>>>> + static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>> + {
>>>> + return __svt;
>>>> + }
>>>>
>>>> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>> for the absence of is_nothrow_convertible (basically the same thing I
>>>> did in LWG 2993's PR).
>>>
>>> Agreed, that makes very much sense. I will adjust the P/R, but before
>>> I resubmit I would like to get feedback whether the other two compare
>>> functions also should become conditionally noexcept.
>>
>> Locally I have now performed the sole change of the _S_to_string_view
>> declaration getting rid of the template, but would also like to gather
>> feedback from the maintainers whether I should also change the form of
>> the conditional noexcept to use the expression
>>
>> noexcept(_S_to_string_view(__t))
>>
>> instead of the current
>>
>> is_same<_Tp, __sv_type>::value
>>
>> as suggested by Tim Song.
>>
>> I'm asking also, because I have a paper proposing to standardize
>> is_nothrow_convertible submitted for the upcoming C++ mailing - This
>> would be one of the first applications in the library ;-)
>
>A slightly revised patch update: It replaces the _S_to_string_view
>template by a simpler _S_to_string_view function as of Tim Song's
>suggestion, but still uses the simplified noexcept specification
>deferring it to a future application case for is_nothrow_convertible.
>Furthermore now all three compare function templates are now
>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>Wakely.
I've committed this, after some whitespace fixes and testing.
Thanks!
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-09-04 15:48 ` Jonathan Wakely
@ 2017-09-11 16:55 ` Jonathan Wakely
2017-09-20 15:36 ` Jonathan Wakely
1 sibling, 0 replies; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-11 16:55 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 2577 bytes --]
On 04/09/17 16:48 +0100, Jonathan Wakely wrote:
>On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>>>On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>>><daniel.kruegler@gmail.com> wrote:
>>>>>>+ // Performs an implicit conversion from _Tp to __sv_type.
>>>>>>+ template<typename _Tp>
>>>>>>+ static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>>>+ {
>>>>>>+ return __svt;
>>>>>>+ }
>>>>>
>>>>>I might have gone for
>>>>>
>>>>>+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>>>+ {
>>>>>+ return __svt;
>>>>>+ }
>>>>>
>>>>>With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>>>for the absence of is_nothrow_convertible (basically the same thing I
>>>>>did in LWG 2993's PR).
>>>>
>>>>Agreed, that makes very much sense. I will adjust the P/R, but before
>>>>I resubmit I would like to get feedback whether the other two compare
>>>>functions also should become conditionally noexcept.
>>>
>>>Locally I have now performed the sole change of the _S_to_string_view
>>>declaration getting rid of the template, but would also like to gather
>>>feedback from the maintainers whether I should also change the form of
>>>the conditional noexcept to use the expression
>>>
>>>noexcept(_S_to_string_view(__t))
>>>
>>>instead of the current
>>>
>>>is_same<_Tp, __sv_type>::value
>>>
>>>as suggested by Tim Song.
>>>
>>>I'm asking also, because I have a paper proposing to standardize
>>>is_nothrow_convertible submitted for the upcoming C++ mailing - This
>>>would be one of the first applications in the library ;-)
>>
>>A slightly revised patch update: It replaces the _S_to_string_view
>>template by a simpler _S_to_string_view function as of Tim Song's
>>suggestion, but still uses the simplified noexcept specification
>>deferring it to a future application case for is_nothrow_convertible.
>>Furthermore now all three compare function templates are now
>>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>>Wakely.
>
>I've committed this, after some whitespace fixes and testing.
>
>Thanks!
We also need this tweak, to account for the fact that the old
std::string has this signature:
basic_string& replace(iterator __i1, iterator __i2,
initializer_list<_CharT> __l)
Tested powerpc64le-linux, committed to trunk.
[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 895 bytes --]
commit c435fd7ed919ae54fc8f730844c7466822787ff8
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Sep 11 17:29:34 2017 +0100
Adjust test to pass with old std::string
* testsuite/21_strings/basic_string/lwg2946.cc: Adjust for
compatibility with old COW std::string.
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc b/libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc
index 74d5a5c89a7..fe1f15553fb 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/lwg2946.cc
@@ -29,7 +29,7 @@ int main()
s.assign({"abc", 1});
s.insert(0, {"abc", 1});
s.replace(0, 1, {"abc", 1});
- s.replace(s.cbegin(), s.cbegin(), {"abc", 1});
+ s.replace(s.begin(), s.begin(), {"abc", 1});
s.find({"abc", 1});
s.rfind({"abc", 1});
s.find_first_of({"abc", 1});
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-09-04 15:48 ` Jonathan Wakely
2017-09-11 16:55 ` Jonathan Wakely
@ 2017-09-20 15:36 ` Jonathan Wakely
2017-09-20 16:52 ` Jonathan Wakely
1 sibling, 1 reply; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-20 15:36 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
On 04/09/17 16:48 +0100, Jonathan Wakely wrote:
>On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>>>On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>>><daniel.kruegler@gmail.com> wrote:
>>>>>>+ // Performs an implicit conversion from _Tp to __sv_type.
>>>>>>+ template<typename _Tp>
>>>>>>+ static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>>>+ {
>>>>>>+ return __svt;
>>>>>>+ }
>>>>>
>>>>>I might have gone for
>>>>>
>>>>>+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>>>+ {
>>>>>+ return __svt;
>>>>>+ }
>>>>>
>>>>>With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>>>for the absence of is_nothrow_convertible (basically the same thing I
>>>>>did in LWG 2993's PR).
>>>>
>>>>Agreed, that makes very much sense. I will adjust the P/R, but before
>>>>I resubmit I would like to get feedback whether the other two compare
>>>>functions also should become conditionally noexcept.
>>>
>>>Locally I have now performed the sole change of the _S_to_string_view
>>>declaration getting rid of the template, but would also like to gather
>>>feedback from the maintainers whether I should also change the form of
>>>the conditional noexcept to use the expression
>>>
>>>noexcept(_S_to_string_view(__t))
>>>
>>>instead of the current
>>>
>>>is_same<_Tp, __sv_type>::value
>>>
>>>as suggested by Tim Song.
>>>
>>>I'm asking also, because I have a paper proposing to standardize
>>>is_nothrow_convertible submitted for the upcoming C++ mailing - This
>>>would be one of the first applications in the library ;-)
>>
>>A slightly revised patch update: It replaces the _S_to_string_view
>>template by a simpler _S_to_string_view function as of Tim Song's
>>suggestion, but still uses the simplified noexcept specification
>>deferring it to a future application case for is_nothrow_convertible.
>>Furthermore now all three compare function templates are now
>>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>>Wakely.
>
>I've committed this, after some whitespace fixes and testing.
>
>Thanks!
This change causes two regressions in C++17 mode, see
https://gcc.gnu.org/ml/gcc-testresults/2017-09/msg01674.html
FAIL: 21_strings/basic_string/cons/char/moveable2.cc execution test
FAIL: 21_strings/basic_string/cons/wchar_t/moveable2.cc execution test
Here's a reduced version of that test, which passes in C++14 and fails
in C++17:
#include <string>
#include <assert.h>
class tstring : public std::string
{
public:
tstring() : std::string() {}
tstring(tstring&& s) : std::string(std::move(s)) {}
};
int main()
{
tstring b;
b.push_back('1');
tstring c(std::move(b));
assert( c.size() == 1 && c[0] == '1' );
assert( b.size() == 0 );
}
The second assertion fails, because this mem-initializer:
tstring(tstring&& s) : std::string(std::move(s)) {}
now prefers to use the new constructor:
basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
because tstring is convertible to string_view.
This turns a non-allocating move into an allocating copy.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-09-20 15:36 ` Jonathan Wakely
@ 2017-09-20 16:52 ` Jonathan Wakely
2017-09-20 18:00 ` Jonathan Wakely
0 siblings, 1 reply; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-20 16:52 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
On 20/09/17 16:36 +0100, Jonathan Wakely wrote:
>On 04/09/17 16:48 +0100, Jonathan Wakely wrote:
>>On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>>>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>>2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>>>>On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>>>><daniel.kruegler@gmail.com> wrote:
>>>>>>>+ // Performs an implicit conversion from _Tp to __sv_type.
>>>>>>>+ template<typename _Tp>
>>>>>>>+ static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>>>>+ {
>>>>>>>+ return __svt;
>>>>>>>+ }
>>>>>>
>>>>>>I might have gone for
>>>>>>
>>>>>>+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>>>>+ {
>>>>>>+ return __svt;
>>>>>>+ }
>>>>>>
>>>>>>With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>>>>for the absence of is_nothrow_convertible (basically the same thing I
>>>>>>did in LWG 2993's PR).
>>>>>
>>>>>Agreed, that makes very much sense. I will adjust the P/R, but before
>>>>>I resubmit I would like to get feedback whether the other two compare
>>>>>functions also should become conditionally noexcept.
>>>>
>>>>Locally I have now performed the sole change of the _S_to_string_view
>>>>declaration getting rid of the template, but would also like to gather
>>>>feedback from the maintainers whether I should also change the form of
>>>>the conditional noexcept to use the expression
>>>>
>>>>noexcept(_S_to_string_view(__t))
>>>>
>>>>instead of the current
>>>>
>>>>is_same<_Tp, __sv_type>::value
>>>>
>>>>as suggested by Tim Song.
>>>>
>>>>I'm asking also, because I have a paper proposing to standardize
>>>>is_nothrow_convertible submitted for the upcoming C++ mailing - This
>>>>would be one of the first applications in the library ;-)
>>>
>>>A slightly revised patch update: It replaces the _S_to_string_view
>>>template by a simpler _S_to_string_view function as of Tim Song's
>>>suggestion, but still uses the simplified noexcept specification
>>>deferring it to a future application case for is_nothrow_convertible.
>>>Furthermore now all three compare function templates are now
>>>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>>>Wakely.
>>
>>I've committed this, after some whitespace fixes and testing.
>>
>>Thanks!
>
>This change causes two regressions in C++17 mode, see
>https://gcc.gnu.org/ml/gcc-testresults/2017-09/msg01674.html
>
>FAIL: 21_strings/basic_string/cons/char/moveable2.cc execution test
>FAIL: 21_strings/basic_string/cons/wchar_t/moveable2.cc execution test
>
>Here's a reduced version of that test, which passes in C++14 and fails
>in C++17:
>
>#include <string>
>#include <assert.h>
>
>class tstring : public std::string
>{
>public:
> tstring() : std::string() {}
> tstring(tstring&& s) : std::string(std::move(s)) {}
>};
>
>int main()
>{
> tstring b;
> b.push_back('1');
> tstring c(std::move(b));
> assert( c.size() == 1 && c[0] == '1' );
> assert( b.size() == 0 );
>}
>
>The second assertion fails, because this mem-initializer:
>
> tstring(tstring&& s) : std::string(std::move(s)) {}
>
>now prefers to use the new constructor:
>
> basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
>
>because tstring is convertible to string_view.
>
>This turns a non-allocating move into an allocating copy.
This patch fixes the failure above, I'm testing it now.
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -115,6 +115,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
template<typename _Tp, typename _Res>
using _If_sv = enable_if_t<
__and_<is_convertible<const _Tp&, __sv_type>,
+ __not_<is_convertible<const _Tp*, const basic_string*>>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-09-20 16:52 ` Jonathan Wakely
@ 2017-09-20 18:00 ` Jonathan Wakely
2017-09-20 22:03 ` Jonathan Wakely
0 siblings, 1 reply; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-20 18:00 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 4334 bytes --]
On 20/09/17 17:52 +0100, Jonathan Wakely wrote:
>On 20/09/17 16:36 +0100, Jonathan Wakely wrote:
>>On 04/09/17 16:48 +0100, Jonathan Wakely wrote:
>>>On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>>>>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>>2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>>>2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>>>>>On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>>>>><daniel.kruegler@gmail.com> wrote:
>>>>>>>>+ // Performs an implicit conversion from _Tp to __sv_type.
>>>>>>>>+ template<typename _Tp>
>>>>>>>>+ static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>>>>>+ {
>>>>>>>>+ return __svt;
>>>>>>>>+ }
>>>>>>>
>>>>>>>I might have gone for
>>>>>>>
>>>>>>>+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>>>>>+ {
>>>>>>>+ return __svt;
>>>>>>>+ }
>>>>>>>
>>>>>>>With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>>>>>for the absence of is_nothrow_convertible (basically the same thing I
>>>>>>>did in LWG 2993's PR).
>>>>>>
>>>>>>Agreed, that makes very much sense. I will adjust the P/R, but before
>>>>>>I resubmit I would like to get feedback whether the other two compare
>>>>>>functions also should become conditionally noexcept.
>>>>>
>>>>>Locally I have now performed the sole change of the _S_to_string_view
>>>>>declaration getting rid of the template, but would also like to gather
>>>>>feedback from the maintainers whether I should also change the form of
>>>>>the conditional noexcept to use the expression
>>>>>
>>>>>noexcept(_S_to_string_view(__t))
>>>>>
>>>>>instead of the current
>>>>>
>>>>>is_same<_Tp, __sv_type>::value
>>>>>
>>>>>as suggested by Tim Song.
>>>>>
>>>>>I'm asking also, because I have a paper proposing to standardize
>>>>>is_nothrow_convertible submitted for the upcoming C++ mailing - This
>>>>>would be one of the first applications in the library ;-)
>>>>
>>>>A slightly revised patch update: It replaces the _S_to_string_view
>>>>template by a simpler _S_to_string_view function as of Tim Song's
>>>>suggestion, but still uses the simplified noexcept specification
>>>>deferring it to a future application case for is_nothrow_convertible.
>>>>Furthermore now all three compare function templates are now
>>>>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>>>>Wakely.
>>>
>>>I've committed this, after some whitespace fixes and testing.
>>>
>>>Thanks!
>>
>>This change causes two regressions in C++17 mode, see
>>https://gcc.gnu.org/ml/gcc-testresults/2017-09/msg01674.html
>>
>>FAIL: 21_strings/basic_string/cons/char/moveable2.cc execution test
>>FAIL: 21_strings/basic_string/cons/wchar_t/moveable2.cc execution test
>>
>>Here's a reduced version of that test, which passes in C++14 and fails
>>in C++17:
>>
>>#include <string>
>>#include <assert.h>
>>
>>class tstring : public std::string
>>{
>>public:
>>tstring() : std::string() {}
>>tstring(tstring&& s) : std::string(std::move(s)) {}
>>};
>>
>>int main()
>>{
>>tstring b;
>>b.push_back('1');
>>tstring c(std::move(b));
>>assert( c.size() == 1 && c[0] == '1' );
>>assert( b.size() == 0 );
>>}
>>
>>The second assertion fails, because this mem-initializer:
>>
>>tstring(tstring&& s) : std::string(std::move(s)) {}
>>
>>now prefers to use the new constructor:
>>
>>basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
>>
>>because tstring is convertible to string_view.
>>
>>This turns a non-allocating move into an allocating copy.
>
>This patch fixes the failure above, I'm testing it now.
>
>--- a/libstdc++-v3/include/bits/basic_string.h
>+++ b/libstdc++-v3/include/bits/basic_string.h
>@@ -115,6 +115,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> template<typename _Tp, typename _Res>
> using _If_sv = enable_if_t<
> __and_<is_convertible<const _Tp&, __sv_type>,
>+ __not_<is_convertible<const _Tp*, const basic_string*>>,
> __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
> _Res>;
>
>
I'm committing this to fix the regression. If the final LWG 2946
resolution does something different we can change it again.
Tested powerpc64le-linux, committed to trunk.
I'll start another test run with all variations ...
[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 5025 bytes --]
commit 45143c77f09ff9ebe27761bca81ccd4f9f928d9b
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Sep 20 17:56:53 2017 +0100
PR libstdc++/79162 Fix std::string regression due to LWG 2946
PR libstdc++/79162
* include/bits/basic_string.h (basic_string::_If_sv): Remove from the
overload set when the argument is derived from basic_string.
* testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc: New
test.
* testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc:
New test.
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index 0ef139b2c2b..8a382d5640c 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -115,6 +115,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
template<typename _Tp, typename _Res>
using _If_sv = enable_if_t<
__and_<is_convertible<const _Tp&, __sv_type>,
+ __not_<is_convertible<const _Tp*, const basic_string*>>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc
new file mode 100644
index 00000000000..88be60d05ab
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc
@@ -0,0 +1,53 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+// Copyright (C) 2011-2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// NOTE: This makes use of the fact that we know how moveable
+// is implemented on string (via swap). If the implementation changed
+// this test may begin to fail.
+
+#include <string>
+#include <utility>
+#include <testsuite_hooks.h>
+
+class tstring : public std::basic_string<char>
+{
+public:
+ tstring() : std::basic_string<char>() {}
+ tstring(tstring&& s) : std::basic_string<char>(std::move(s)) {}
+ tstring& operator=(tstring&& s) = default;
+};
+
+void test01()
+{
+ tstring a, b;
+ a.push_back('1');
+ b = std::move(a);
+ VERIFY( b.size() == 1 && b[0] == '1' && a.size() == 0 );
+
+ tstring c(std::move(b));
+ VERIFY( c.size() == 1 && c[0] == '1' );
+ VERIFY( b.size() == 0 );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc b/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc
new file mode 100644
index 00000000000..63684de68a6
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc
@@ -0,0 +1,53 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+// Copyright (C) 2011-2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// NOTE: This makes use of the fact that we know how moveable
+// is implemented on string (via swap). If the implementation changed
+// this test may begin to fail.
+
+#include <string>
+#include <utility>
+#include <testsuite_hooks.h>
+
+class tstring : public std::basic_string<wchar_t>
+{
+public:
+ tstring() : std::basic_string<wchar_t>() {}
+ tstring(tstring&& s) : std::basic_string<wchar_t>(std::move(s)) {}
+ tstring& operator=(tstring&& s) = default;
+};
+
+void test01()
+{
+ tstring a, b;
+ a.push_back(L'1');
+ b = std::move(a);
+ VERIFY( b.size() == 1 && b[0] == L'1' && a.size() == 0 );
+
+ tstring c(std::move(b));
+ VERIFY( c.size() == 1 && c[0] == L'1' );
+ VERIFY( b.size() == 0 );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
2017-09-20 18:00 ` Jonathan Wakely
@ 2017-09-20 22:03 ` Jonathan Wakely
0 siblings, 0 replies; 12+ messages in thread
From: Jonathan Wakely @ 2017-09-20 22:03 UTC (permalink / raw)
To: Daniel Krügler; +Cc: Tim Song, libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 4605 bytes --]
On 20/09/17 18:59 +0100, Jonathan Wakely wrote:
>On 20/09/17 17:52 +0100, Jonathan Wakely wrote:
>>On 20/09/17 16:36 +0100, Jonathan Wakely wrote:
>>>On 04/09/17 16:48 +0100, Jonathan Wakely wrote:
>>>>On 30/07/17 15:01 +0200, Daniel Krügler wrote:
>>>>>2017-07-28 22:40 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>>>2017-07-28 22:29 GMT+02:00 Daniel Krügler <daniel.kruegler@gmail.com>:
>>>>>>>2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
>>>>>>>>On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
>>>>>>>><daniel.kruegler@gmail.com> wrote:
>>>>>>>>>+ // Performs an implicit conversion from _Tp to __sv_type.
>>>>>>>>>+ template<typename _Tp>
>>>>>>>>>+ static __sv_type _S_to_string_view(const _Tp& __svt)
>>>>>>>>>+ {
>>>>>>>>>+ return __svt;
>>>>>>>>>+ }
>>>>>>>>
>>>>>>>>I might have gone for
>>>>>>>>
>>>>>>>>+ static __sv_type _S_to_string_view(__sv_type __svt) noexcept
>>>>>>>>+ {
>>>>>>>>+ return __svt;
>>>>>>>>+ }
>>>>>>>>
>>>>>>>>With that, we can also use noexcept(_S_to_string_view(__t)) to make up
>>>>>>>>for the absence of is_nothrow_convertible (basically the same thing I
>>>>>>>>did in LWG 2993's PR).
>>>>>>>
>>>>>>>Agreed, that makes very much sense. I will adjust the P/R, but before
>>>>>>>I resubmit I would like to get feedback whether the other two compare
>>>>>>>functions also should become conditionally noexcept.
>>>>>>
>>>>>>Locally I have now performed the sole change of the _S_to_string_view
>>>>>>declaration getting rid of the template, but would also like to gather
>>>>>>feedback from the maintainers whether I should also change the form of
>>>>>>the conditional noexcept to use the expression
>>>>>>
>>>>>>noexcept(_S_to_string_view(__t))
>>>>>>
>>>>>>instead of the current
>>>>>>
>>>>>>is_same<_Tp, __sv_type>::value
>>>>>>
>>>>>>as suggested by Tim Song.
>>>>>>
>>>>>>I'm asking also, because I have a paper proposing to standardize
>>>>>>is_nothrow_convertible submitted for the upcoming C++ mailing - This
>>>>>>would be one of the first applications in the library ;-)
>>>>>
>>>>>A slightly revised patch update: It replaces the _S_to_string_view
>>>>>template by a simpler _S_to_string_view function as of Tim Song's
>>>>>suggestion, but still uses the simplified noexcept specification
>>>>>deferring it to a future application case for is_nothrow_convertible.
>>>>>Furthermore now all three compare function templates are now
>>>>>(conditionally) noexcept by an (off-list) suggestion from Jonathan
>>>>>Wakely.
>>>>
>>>>I've committed this, after some whitespace fixes and testing.
>>>>
>>>>Thanks!
>>>
>>>This change causes two regressions in C++17 mode, see
>>>https://gcc.gnu.org/ml/gcc-testresults/2017-09/msg01674.html
>>>
>>>FAIL: 21_strings/basic_string/cons/char/moveable2.cc execution test
>>>FAIL: 21_strings/basic_string/cons/wchar_t/moveable2.cc execution test
>>>
>>>Here's a reduced version of that test, which passes in C++14 and fails
>>>in C++17:
>>>
>>>#include <string>
>>>#include <assert.h>
>>>
>>>class tstring : public std::string
>>>{
>>>public:
>>>tstring() : std::string() {}
>>>tstring(tstring&& s) : std::string(std::move(s)) {}
>>>};
>>>
>>>int main()
>>>{
>>>tstring b;
>>>b.push_back('1');
>>>tstring c(std::move(b));
>>>assert( c.size() == 1 && c[0] == '1' );
>>>assert( b.size() == 0 );
>>>}
>>>
>>>The second assertion fails, because this mem-initializer:
>>>
>>>tstring(tstring&& s) : std::string(std::move(s)) {}
>>>
>>>now prefers to use the new constructor:
>>>
>>>basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
>>>
>>>because tstring is convertible to string_view.
>>>
>>>This turns a non-allocating move into an allocating copy.
>>
>>This patch fixes the failure above, I'm testing it now.
>>
>>--- a/libstdc++-v3/include/bits/basic_string.h
>>+++ b/libstdc++-v3/include/bits/basic_string.h
>>@@ -115,6 +115,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
>> template<typename _Tp, typename _Res>
>> using _If_sv = enable_if_t<
>> __and_<is_convertible<const _Tp&, __sv_type>,
>>+ __not_<is_convertible<const _Tp*, const basic_string*>>,
>> __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
>> _Res>;
>>
>>
>
>I'm committing this to fix the regression. If the final LWG 2946
>resolution does something different we can change it again.
>
>Tested powerpc64le-linux, committed to trunk.
>
>I'll start another test run with all variations ...
That test run revealed I forgot to make the same change to the _If_sv
helper in the old std::basic_string.
[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 981 bytes --]
commit ab3a6ce803de3d21325bb82978f1f6d61c5cb4e2
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Sep 20 22:48:04 2017 +0100
PR libstdc++/79162 Fix std::string regression due to LWG 2946 (old ABI)
PR libstdc++/79162
* include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
(basic_string::_If_sv): Remove from the overload set when the
argument is derived from basic_string.
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index 8a382d5640c..a4b81137571 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -3439,6 +3439,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
template<typename _Tp, typename _Res>
using _If_sv = enable_if_t<
__and_<is_convertible<const _Tp&, __sv_type>,
+ __not_<is_convertible<const _Tp*, const basic_string*>>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)
@ 2017-07-28 20:07 Daniel Krügler
0 siblings, 0 replies; 12+ messages in thread
From: Daniel Krügler @ 2017-07-28 20:07 UTC (permalink / raw)
To: gcc-patches List, libstdc
[-- Attachment #1: Type: text/plain, Size: 1865 bytes --]
This patch attempts to solve an issue in basic_string after adding
string_view to several functions that came in during incomplete patch
of LWG 2758/LWG 2946, in short: Functions that take a string_view
parameter value are now replaced by constrained templates taking const
T& that is convertible to string_view. The patch also attempts to
complete the LWG 2946 P/R. With the absence of the
std::is_nothrow_convertible traits, the P/R also restores some of the
lost noexcept specifications of const functions (find, compare, etc)
by conditional noexcept simply comparing whether T is the same type as
string_view.
During that fix two related, minor problems where found and also fixed:
a) Member
int compare(basic_string_view<charT, traits> sv) const;
should be noexcept according the spec, but this function wasn't at
all. Since the changes for LWG 2946 required me to touch the noexcept
specifier anyway I replaced it by the conditional noexcept mentioned
above. I do not know what the general policy for "narrow contract"
functions is in libstdc++ code, I therefore didn't touch the also
missing (but optional) noexcept for
int compare(size_type pos1, size_type n1,basic_string_view<charT,
traits> sv) const;
template<class T>
int compare(size_type pos1, size_type n1, const T& t, size_type pos2,
size_type n2 = npos) const;
If wanted, I can apply the same conditional noexcept here as well.
b) Two constructors using the const T& -> string_view conversion did
this via explicit conversion instead of implicit conversion. This
difference can be observed by user-code and in certain cases either a
well-formed program can become ill-formed or may perform different
runtime behaviour (Overloaded conversion operators, one explicit, the
other implicit).
This patch is *untested*, because I cannot make the tests run on my
Windows system.
Thanks,
- Daniel
[-- Attachment #2: ChangeLog_79162.patch --]
[-- Type: application/octet-stream, Size: 2115 bytes --]
Index: ChangeLog
===================================================================
--- ChangeLog (revision 250685)
+++ ChangeLog (working copy)
@@ -1,3 +1,34 @@
+2017-07-28 Daniel Kruegler <daniel.kruegler@gmail.com>
+
+ PR libstdc++/79162
+ Implement LWG 2946, LWG 2758's resolution missed further corrections
+ * include/bits/basic_string.h (basic_string::compare): Added missing
+ required noexcept specification.
+ * include/bits/basic_string.h (basic_string): Introduce internal
+ _S_to_string_view and __sv_wrapper for implicit string_view conversion.
+ * include/bits/basic_string.h (basic_string::basic_string): Fix explicit
+ string_view conversion by implicit conversion using _S_to_string_view and
+ __sv_wrapper.
+ * include/bits/basic_string.h (basic_string): Introduce internal
+ basic_string(__sv_wrapper, Alloc) constructor.
+ * include/bits/basic_string.h (basic_string): Fix operator=(T) template
+ by operator=(const T&) template for uncopyable types (79162).
+ * include/bits/basic_string.h (basic_string::operator+=,
+ basic_string::append, basic_string::assign, basic_string::insert,
+ basic_string::replace, basic_string::find, basic_string::rfind,
+ basic_string::find_first_of, basic_string::find_last_of,
+ basic_string::find_first_not_of, basic_string::find_last_not_of,
+ basic_string::compare): Replace __sv_type argument by template const T&
+ (LWG 2946) and corrected documentation describing __sv_type argument.
+ * include/bits/basic_string.h (basic_string::find, basic_string::rfind,
+ basic_string::find_first_of, basic_string::find_last_of,
+ basic_string::find_first_not_of, basic_string::find_last_not_of,
+ basic_string::compare): Replace unconditional noexcept specification by
+ conditional noexcept specification to balance the remove of noexcept by
+ LWG 2946.
+ * testsuite/21_strings/basic_string/79162.cc: New.
+ * testsuite/21_strings/basic_string/lwg2946.cc: New.
+
2017-07-26 Jonathan Wakely <jwakely@redhat.com>
* testsuite/27_io/basic_fstream/53984.cc: Fix test.
[-- Attachment #3: 79162.patch --]
[-- Type: application/octet-stream, Size: 38505 bytes --]
Index: include/bits/basic_string.h
===================================================================
--- include/bits/basic_string.h (revision 250685)
+++ include/bits/basic_string.h (working copy)
@@ -117,6 +117,23 @@
__and_<is_convertible<const _Tp&, __sv_type>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
+
+ // Performs an implicit conversion from _Tp to __sv_type.
+ template<typename _Tp>
+ static __sv_type _S_to_string_view(const _Tp& __svt)
+ {
+ return __svt;
+ }
+
+ // Wraps a string_view by explicit conversion and thus
+ // allows to add an internal constructor that does not
+ // participate in overload resolution when a string_view
+ // is provided.
+ struct __sv_wrapper
+ {
+ explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) {}
+ __sv_type _M_sv;
+ };
#endif
// Use empty-base optimization: http://www.cantrip.org/emptyopt.html
@@ -593,7 +610,7 @@
#if __cplusplus > 201402L
/**
* @brief Construct string from a substring of a string_view.
- * @param __t Source string view.
+ * @param __t Source object convertible to string view.
* @param __pos The index of the first character to copy from __t.
* @param __n The number of characters to copy from __t.
* @param __a Allocator to use.
@@ -601,16 +618,27 @@
template<typename _Tp, typename = _If_sv<_Tp, void>>
basic_string(const _Tp& __t, size_type __pos, size_type __n,
const _Alloc& __a = _Alloc())
- : basic_string(__sv_type(__t).substr(__pos, __n), __a) { }
-
+ : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
+
/**
* @brief Construct string from a string_view.
- * @param __sv Source string view.
+ * @param __t Source object convertible to string view.
* @param __a Allocator to use (default is default allocator).
*/
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
explicit
- basic_string(__sv_type __sv, const _Alloc& __a = _Alloc())
- : basic_string(__sv.data(), __sv.size(), __a) { }
+ basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
+ : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
+
+ /**
+ * @brief Only internally used: Construct string from a string view
+ * wrapper.
+ * @param __svw string view wrapper.
+ * @param __a Allocator to use.
+ */
+ explicit
+ basic_string(__sv_wrapper __svw, const _Alloc& __a)
+ : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
#endif // C++17
/**
@@ -756,12 +784,12 @@
#if __cplusplus > 201402L
/**
* @brief Set value to string constructed from a string_view.
- * @param __sv A string_view.
+ * @param __svt An object convertible to string_view.
*/
- template<typename _Tp>
- _If_sv<_Tp, basic_string&>
- operator=(_Tp __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(const _Tp& __svt)
+ { return this->assign(__svt); }
/**
* @brief Convert to a string_view.
@@ -1157,12 +1185,13 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt An object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- operator+=(__sv_type __sv)
- { return this->append(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator+=(const _Tp& __svt)
+ { return this->append(__svt); }
#endif // C++17
/**
@@ -1265,29 +1294,33 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt An object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- append(__sv_type __sv)
- { return this->append(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->append(__sv.data(), __sv.size());
+ }
/**
* @brief Append a range of characters from a string_view.
- * @param __sv The string_view to be appended from.
+ * @param __svt An object convertible to string_view to be appended from.
* @param __pos The position in the string_view to append from.
* @param __n The number of characters to append from the string_view.
* @return Reference to this string.
*/
template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- append(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return _M_append(__sv.data()
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return _M_append(__sv.data()
+ __sv._M_check(__pos, "basic_string::append"),
__sv._M_limit(__pos, __n));
- }
+ }
#endif // C++17
/**
@@ -1433,29 +1466,33 @@
#if __cplusplus > 201402L
/**
* @brief Set value from a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @return Reference to this string.
*/
- basic_string&
- assign(__sv_type __sv)
- { return this->assign(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->assign(__sv.data(), __sv.size());
+ }
/**
* @brief Set value from a range of characters in a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @param __pos The position in the string_view to assign from.
* @param __n The number of characters to assign.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return _M_replace(size_type(0), this->size(), __sv.data()
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return _M_replace(size_type(0), this->size(), __sv.data()
+ __sv._M_check(__pos, "basic_string::assign"),
__sv._M_limit(__pos, __n));
- }
+ }
#endif // C++17
#if __cplusplus >= 201103L
@@ -1692,32 +1729,36 @@
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- insert(size_type __pos, __sv_type __sv)
- { return this->insert(__pos, __sv.data(), __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->insert(__pos, __sv.data(), __sv.size());
+ }
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos Iterator referencing position in string_view to insert
* from.
* @param __n The number of characters to insert.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- insert(size_type __pos1, const _Tp& __svt,
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos1, const _Tp& __svt,
size_type __pos2, size_type __n = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, size_type(0), __sv.data()
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, size_type(0), __sv.data()
+ __sv._M_check(__pos2, "basic_string::insert"),
__sv._M_limit(__pos2, __n));
- }
+ }
#endif // C++17
/**
@@ -2120,32 +2161,36 @@
* @brief Replace range of characters with string_view.
* @param __pos The position to replace at.
* @param __n The number of characters to replace.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- replace(size_type __pos, size_type __n, __sv_type __sv)
- { return this->replace(__pos, __n, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos, size_type __n, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos, __n, __sv.data(), __sv.size());
+ }
/**
* @brief Replace range of characters with string_view.
* @param __pos1 The position to replace at.
* @param __n1 The number of characters to replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos2 The position in the string_view to insert from.
* @param __n2 The number of characters to insert.
* @return Reference to this string.
*/
- template <typename _Tp>
- _If_sv<_Tp, basic_string&>
- replace(size_type __pos1, size_type __n1, const _Tp& __svt,
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos1, size_type __n1, const _Tp& __svt,
size_type __pos2, size_type __n2 = npos)
- {
- __sv_type __sv = __svt;
- return this->replace(__pos1, __n1, __sv.data()
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, __n1, __sv.data()
+ __sv._M_check(__pos2, "basic_string::replace"),
__sv._M_limit(__pos2, __n2));
- }
+ }
/**
* @brief Replace range of characters with string_view.
@@ -2153,12 +2198,16 @@
to replace at.
* @param __i2 An iterator referencing the end position
for the replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @return Reference to this string.
*/
- basic_string&
- replace(const_iterator __i1, const_iterator __i2, __sv_type __sv)
- { return this->replace(__i1 - begin(), __i2 - __i1, __sv); }
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__i1 - begin(), __i2 - __i1, __sv);
+ }
#endif // C++17
private:
@@ -2288,13 +2337,18 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of start of first occurrence.
*/
- size_type
- find(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2345,13 +2399,18 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of start of last occurrence.
*/
- size_type
- rfind(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->rfind(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ rfind(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->rfind(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2419,13 +2478,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character of a string_view.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2497,13 +2562,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character of string.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2574,13 +2645,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt A object convertible to string_view containing characters
+ * to avoid.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_not_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_not_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2650,13 +2727,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_not_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_not_of(__sv.data(), __pos, __sv.size()); }
+ template <typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -2754,12 +2837,14 @@
#if __cplusplus > 201402L
/**
* @brief Compare to a string_view.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(__sv_type __sv) const
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(const _Tp& __svt) const noexcept(is_same<_Tp, __sv_type>::value)
{
+ __sv_type __sv = __svt;
const size_type __size = this->size();
const size_type __osize = __sv.size();
const size_type __len = std::min(__size, __osize);
@@ -2774,18 +2859,24 @@
* @brief Compare to a string_view.
* @param __pos A position in the string to start comparing from.
* @param __n The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(size_type __pos, size_type __n, __sv_type __sv) const
- { return __sv_type(*this).substr(__pos, __n).compare(__sv); }
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos, size_type __n, const _Tp& __svt) const
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this).substr(__pos, __n).compare(__sv);
+ }
/**
* @brief Compare to a string_view.
* @param __pos1 A position in the string to start comparing from.
* @param __n1 The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @param __pos2 A position in the string_view to start comparing from.
* @param __n2 The number of characters to compare.
* @return Integer < 0, 0, or > 0.
@@ -3348,6 +3439,23 @@
__and_<is_convertible<const _Tp&, __sv_type>,
__not_<is_convertible<const _Tp&, const _CharT*>>>::value,
_Res>;
+
+ // Performs an implicit conversion from _Tp to __sv_type.
+ template<typename _Tp>
+ static __sv_type _S_to_string_view(const _Tp& __svt)
+ {
+ return __svt;
+ }
+
+ // Wraps a string_view by explicit conversion and thus
+ // allows to add an internal constructor that does not
+ // participate in overload resolution when a string_view
+ // is provided.
+ struct __sv_wrapper
+ {
+ explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) {}
+ __sv_type _M_sv;
+ };
#endif
public:
@@ -3474,24 +3582,35 @@
#if __cplusplus > 201402L
/**
* @brief Construct string from a substring of a string_view.
- * @param __t Source string view.
+ * @param __t Source object convertible to string view.
* @param __pos The index of the first character to copy from __t.
* @param __n The number of characters to copy from __t.
* @param __a Allocator to use.
*/
- template<typename _Tp, typename = _If_sv<_Tp, void>>
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
basic_string(const _Tp& __t, size_type __pos, size_type __n,
const _Alloc& __a = _Alloc())
- : basic_string(__sv_type(__t).substr(__pos, __n), __a) { }
-
+ : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
+
/**
* @brief Construct string from a string_view.
- * @param __sv Source string view.
+ * @param __t Source object convertible to string view.
* @param __a Allocator to use (default is default allocator).
*/
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
explicit
- basic_string(__sv_type __sv, const _Alloc& __a = _Alloc())
- : basic_string(__sv.data(), __sv.size(), __a) { }
+ basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
+ : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
+
+ /**
+ * @brief Only internally used: Construct string from a string view
+ * wrapper.
+ * @param __svw string view wrapper.
+ * @param __a Allocator to use.
+ */
+ explicit
+ basic_string(__sv_wrapper __svw, const _Alloc& __a)
+ : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
#endif // C++17
/**
@@ -3562,12 +3681,12 @@
#if __cplusplus > 201402L
/**
* @brief Set value to string constructed from a string_view.
- * @param __sv A string_view.
+ * @param __svt An object convertible to string_view.
*/
- template<typename _Tp>
- _If_sv<_Tp, basic_string&>
- operator=(_Tp __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(const _Tp& __svt)
+ { return this->assign(__svt); }
/**
* @brief Convert to a string_view.
@@ -3984,12 +4103,13 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt The object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- operator+=(__sv_type __sv)
- { return this->append(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator+=(const _Tp& __svt)
+ { return this->append(__svt); }
#endif // C++17
/**
@@ -4075,16 +4195,21 @@
#if __cplusplus > 201402L
/**
* @brief Append a string_view.
- * @param __sv The string_view to be appended.
+ * @param __svt The object convertible to string_view to be appended.
* @return Reference to this string.
*/
- basic_string&
- append(__sv_type __sv)
- { return this->append(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->append(__sv.data(), __sv.size());
+ }
/**
* @brief Append a range of characters from a string_view.
- * @param __sv The string_view to be appended from.
+ * @param __svt The object convertible to string_view to be appended
+ * from.
* @param __pos The position in the string_view to append from.
* @param __n The number of characters to append from the string_view.
* @return Reference to this string.
@@ -4228,16 +4353,20 @@
#if __cplusplus > 201402L
/**
* @brief Set value from a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @return Reference to this string.
*/
- basic_string&
- assign(__sv_type __sv)
- { return this->assign(__sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->assign(__sv.data(), __sv.size());
+ }
/**
* @brief Set value from a range of characters in a string_view.
- * @param __sv The source string_view.
+ * @param __svt The source object convertible to string_view.
* @param __pos The position in the string_view to assign from.
* @param __n The number of characters to assign.
* @return Reference to this string.
@@ -4432,17 +4561,21 @@
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- insert(size_type __pos, __sv_type __sv)
- { return this->insert(__pos, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->insert(__pos, __sv.data(), __sv.size());
+ }
/**
* @brief Insert a string_view.
* @param __pos Iterator referencing position in string to insert at.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos Iterator referencing position in string_view to insert
* from.
* @param __n The number of characters to insert.
@@ -4819,18 +4952,22 @@
* @brief Replace range of characters with string_view.
* @param __pos The position to replace at.
* @param __n The number of characters to replace.
- * @param __sv The string_view to insert.
+ * @param __svt The object convertible to string_view to insert.
* @return Reference to this string.
*/
- basic_string&
- replace(size_type __pos, size_type __n, __sv_type __sv)
- { return this->replace(__pos, __n, __sv.data(), __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos, size_type __n, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos, __n, __sv.data(), __sv.size());
+ }
/**
* @brief Replace range of characters with string_view.
* @param __pos1 The position to replace at.
* @param __n1 The number of characters to replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @param __pos2 The position in the string_view to insert from.
* @param __n2 The number of characters to insert.
* @return Reference to this string.
@@ -4852,12 +4989,16 @@
to replace at.
* @param __i2 An iterator referencing the end position
for the replace.
- * @param __sv The string_view to insert from.
+ * @param __svt The object convertible to string_view to insert from.
* @return Reference to this string.
*/
- basic_string&
- replace(const_iterator __i1, const_iterator __i2, __sv_type __sv)
- { return this->replace(__i1 - begin(), __i2 - __i1, __sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__i1 - begin(), __i2 - __i1, __sv);
+ }
#endif // C++17
private:
@@ -5062,13 +5203,18 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of start of first occurrence.
*/
- size_type
- find(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5135,13 +5281,18 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a string_view.
- * @param __sv The string_view to locate.
+ * @param __svt The object convertible to string_view to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of start of last occurrence.
*/
- size_type
- rfind(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->rfind(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ rfind(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->rfind(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5213,13 +5364,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character of a string_view.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5291,13 +5448,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character of string.
- * @param __sv A string_view containing characters to locate.
+ * @param __svt An object convertible to string_view containing
+ * characters to locate.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5366,13 +5529,19 @@
#if __cplusplus > 201402L
/**
* @brief Find position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search from (default 0).
* @return Index of first occurrence.
*/
- size_type
- find_first_not_of(__sv_type __sv, size_type __pos = 0) const noexcept
- { return this->find_first_not_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_first_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5442,13 +5611,19 @@
#if __cplusplus > 201402L
/**
* @brief Find last position of a character not in a string_view.
- * @param __sv A string_view containing characters to avoid.
+ * @param __svt An object convertible to string_view containing
+ * characters to avoid.
* @param __pos Index of character to search back from (default end).
* @return Index of last occurrence.
*/
- size_type
- find_last_not_of(__sv_type __sv, size_type __pos = npos) const noexcept
- { return this->find_last_not_of(__sv.data(), __pos, __sv.size()); }
+ template<typename _Tp>
+ _If_sv<_Tp, size_type>
+ find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
+ noexcept(is_same<_Tp, __sv_type>::value)
+ {
+ __sv_type __sv = __svt;
+ return this->find_last_not_of(__sv.data(), __pos, __sv.size());
+ }
#endif // C++17
/**
@@ -5498,12 +5673,14 @@
#if __cplusplus > 201402L
/**
* @brief Compare to a string_view.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(__sv_type __sv) const
+ template<typename _Tp>
+ _If_sv<_Tp, int>
+ compare(const _Tp& __svt) const noexcept(is_same<_Tp, __sv_type>::value)
{
+ __sv_type __sv = __svt;
const size_type __size = this->size();
const size_type __osize = __sv.size();
const size_type __len = std::min(__size, __osize);
@@ -5518,18 +5695,24 @@
* @brief Compare to a string_view.
* @param __pos A position in the string to start comparing from.
* @param __n The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @return Integer < 0, 0, or > 0.
*/
- int
- compare(size_type __pos, size_type __n, __sv_type __sv) const
- { return __sv_type(*this).substr(__pos, __n).compare(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos, size_type __n, const _Tp& __svt) const
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this).substr(__pos, __n).compare(__sv);
+ }
/**
* @brief Compare to a string_view.
* @param __pos1 A position in the string to start comparing from.
* @param __n1 The number of characters to compare.
- * @param __sv A string_view to compare against.
+ * @param __svt An object convertible to string_view to compare
+ * against.
* @param __pos2 A position in the string_view to start comparing from.
* @param __n2 The number of characters to compare.
* @return Integer < 0, 0, or > 0.
Index: testsuite/21_strings/basic_string/79162.cc
===================================================================
--- testsuite/21_strings/basic_string/79162.cc (nonexistent)
+++ testsuite/21_strings/basic_string/79162.cc (working copy)
@@ -0,0 +1,37 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+
+template <class DataType>
+class opt : public DataType
+{
+ opt(const opt &) = delete;
+ opt &operator=(const opt &) = delete;
+public:
+ opt() {}
+};
+
+int main()
+{
+ opt<std::string> PGOTestProfileFile;
+ std::string ProfileFileName;
+ ProfileFileName = PGOTestProfileFile;
+}
Index: testsuite/21_strings/basic_string/lwg2946.cc
===================================================================
--- testsuite/21_strings/basic_string/lwg2946.cc (nonexistent)
+++ testsuite/21_strings/basic_string/lwg2946.cc (working copy)
@@ -0,0 +1,41 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do compile }
+
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+
+int main()
+{
+ std::string s({"abc", 1});
+ s = {"abc", 1};
+ s += {"abc", 1};
+ s.append({"abc", 1});
+ s.assign({"abc", 1});
+ s.insert(0, {"abc", 1});
+ s.replace(0, 1, {"abc", 1});
+ s.replace(s.cbegin(), s.cbegin(), {"abc", 1});
+ s.find({"abc", 1});
+ s.rfind({"abc", 1});
+ s.find_first_of({"abc", 1});
+ s.find_last_of({"abc", 1});
+ s.find_first_not_of({"abc", 1});
+ s.find_last_not_of({"abc", 1});
+ s.compare({"abc", 1});
+ s.compare(0, 1, {"abc", 1});
+}
^ permalink raw reply [flat|nested] 12+ messages in thread
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[not found] <CAGNvRgCv1Y8a6DGO=p9g8FAve1-UKf53vshqFYtdmWkDUzn8+Q@mail.gmail.com>
2017-07-28 20:26 ` [PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946) Tim Song
2017-07-28 20:29 ` Daniel Krügler
2017-07-28 20:40 ` Daniel Krügler
2017-07-30 13:01 ` Daniel Krügler
2017-08-18 18:27 ` Daniel Krügler
2017-09-04 15:48 ` Jonathan Wakely
2017-09-11 16:55 ` Jonathan Wakely
2017-09-20 15:36 ` Jonathan Wakely
2017-09-20 16:52 ` Jonathan Wakely
2017-09-20 18:00 ` Jonathan Wakely
2017-09-20 22:03 ` Jonathan Wakely
2017-07-28 20:07 Daniel Krügler
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