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* [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const
@ 2014-09-05 20:55 dacamara.cameron at gmail dot com
2014-12-13 23:36 ` [Bug c++/63192] " ville.voutilainen at gmail dot com
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: dacamara.cameron at gmail dot com @ 2014-09-05 20:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63192
Bug ID: 63192
Summary: non-mutable lambda capture by value on reference does
not apply const
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dacamara.cameron at gmail dot com
This is an example taken directly from the standard (5.1.2.19) with a bit of
decoration for output. The last case produces false when it should be true.
int main() {
float x, &r = x;
std::cout<<std::boolalpha;
[=] { // x and r are not captured (appearance in a decltype operand is not
an odr-use)
std::cout<<std::is_same<decltype(x), float>::value<<'\n' // has type
float
<<std::is_same<decltype((x)), float const&>::value<<'\n' // has type
float const& because this lambda
// is not
mutable and x is an lvalue
<<std::is_same<decltype(r), float&>::value<<'\n' // r1 has type
float& (transformation not considered)
<<std::is_same<decltype((r)), float const&>::value; // r2 has type
float const&
}();
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/63192] non-mutable lambda capture by value on reference does not apply const
2014-09-05 20:55 [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const dacamara.cameron at gmail dot com
@ 2014-12-13 23:36 ` ville.voutilainen at gmail dot com
2014-12-13 23:40 ` ville.voutilainen at gmail dot com
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: ville.voutilainen at gmail dot com @ 2014-12-13 23:36 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63192
Ville Voutilainen <ville.voutilainen at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-12-13
CC| |ville.voutilainen at gmail dot com
Ever confirmed|0 |1
Known to fail| |4.8.2, 4.9.1, 5.0
--- Comment #1 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Clang produces the expected result. A reduced testcase without the use of
iostreams would be helpful.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/63192] non-mutable lambda capture by value on reference does not apply const
2014-09-05 20:55 [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const dacamara.cameron at gmail dot com
2014-12-13 23:36 ` [Bug c++/63192] " ville.voutilainen at gmail dot com
@ 2014-12-13 23:40 ` ville.voutilainen at gmail dot com
2021-08-12 22:57 ` pinskia at gcc dot gnu.org
2023-11-10 16:06 ` ppalka at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ville.voutilainen at gmail dot com @ 2014-12-13 23:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63192
--- Comment #2 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Reduced:
template <class, class> struct same {static constexpr bool value = false;};
template <class T> struct same<T, T> {static constexpr bool value = true;};
int main() {
float x, &r = x;
[=] { // x and r are not captured (appearance in a decltype operand is not
an odr-use)
static_assert(same<decltype(x), float>::value, "");
static_assert(same<decltype((x)), float const&>::value, "");
static_assert(same<decltype(r), float&>::value, "");
static_assert(same<decltype((r)), float const&>::value, "");
}();
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/63192] non-mutable lambda capture by value on reference does not apply const
2014-09-05 20:55 [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const dacamara.cameron at gmail dot com
2014-12-13 23:36 ` [Bug c++/63192] " ville.voutilainen at gmail dot com
2014-12-13 23:40 ` ville.voutilainen at gmail dot com
@ 2021-08-12 22:57 ` pinskia at gcc dot gnu.org
2023-11-10 16:06 ` ppalka at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-12 22:57 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63192
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |thiago at kde dot org
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 66672 has been marked as a duplicate of this bug. ***
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/63192] non-mutable lambda capture by value on reference does not apply const
2014-09-05 20:55 [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const dacamara.cameron at gmail dot com
` (2 preceding siblings ...)
2021-08-12 22:57 ` pinskia at gcc dot gnu.org
@ 2023-11-10 16:06 ` ppalka at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ppalka at gcc dot gnu.org @ 2023-11-10 16:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63192
Patrick Palka <ppalka at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |DUPLICATE
Status|NEW |RESOLVED
See Also|https://gcc.gnu.org/bugzill |
|a/show_bug.cgi?id=79620 |
CC| |ppalka at gcc dot gnu.org
--- Comment #8 from Patrick Palka <ppalka at gcc dot gnu.org> ---
This seems to be a dup of the recently fixed PR79620.
*** This bug has been marked as a duplicate of bug 79620 ***
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-11-10 16:06 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2014-09-05 20:55 [Bug c++/63192] New: non-mutable lambda capture by value on reference does not apply const dacamara.cameron at gmail dot com
2014-12-13 23:36 ` [Bug c++/63192] " ville.voutilainen at gmail dot com
2014-12-13 23:40 ` ville.voutilainen at gmail dot com
2021-08-12 22:57 ` pinskia at gcc dot gnu.org
2023-11-10 16:06 ` ppalka at gcc dot gnu.org
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