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From: Jonathan Wakely <redi@gcc.gnu.org>
To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org
Subject: [gcc r11-9297] libstdc++: Simplify std::optional::value()
Date: Wed, 24 Nov 2021 11:51:59 +0000 (GMT) [thread overview]
Message-ID: <20211124115159.392D5385780D@sourceware.org> (raw)
https://gcc.gnu.org/g:20cd18fc47a4e45d8de9710c8ab78188e2638f08
commit r11-9297-g20cd18fc47a4e45d8de9710c8ab78188e2638f08
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Jul 27 14:50:28 2021 +0100
libstdc++: Simplify std::optional::value()
The structure of these functions likely dates from the time before G++
fully supported C++14 extended constexpr, so that the throw expression
had to be the operand of a conditional expression. That is not true now,
so we can use a more straightforward version of the code.
We can also simplify the declaration of __throw_bad_optional_access by
using the C++11-style [[noreturn]] attribute so that a separate
declaration isn't needed.
libstdc++-v3/ChangeLog:
* include/experimental/optional (__throw_bad_optional_access):
Replace GNU attribute with C++11 attribute.
(optional::value, optional::value_or): Use if statements
instead of conditional expressions.
* include/std/optional (__throw_bad_optional_access)
(optional::value, optional::value_or): Likewise.
(cherry picked from commit 9360d6cd1706882dfffd3c7a08b5956c37207a11)
Diff:
---
libstdc++-v3/include/experimental/optional | 56 +++++++++++++-----------------
libstdc++-v3/include/std/optional | 43 +++++++++++------------
2 files changed, 46 insertions(+), 53 deletions(-)
diff --git a/libstdc++-v3/include/experimental/optional b/libstdc++-v3/include/experimental/optional
index ae2418f0500..c1d61d6a0d7 100644
--- a/libstdc++-v3/include/experimental/optional
+++ b/libstdc++-v3/include/experimental/optional
@@ -114,12 +114,8 @@ inline namespace fundamentals_v1
/// @cond undocumented
- void
- __throw_bad_optional_access(const char*)
- __attribute__((__noreturn__));
-
// XXX Does not belong here.
- inline void
+ [[noreturn]] inline void
__throw_bad_optional_access(const char* __s)
{ _GLIBCXX_THROW_OR_ABORT(bad_optional_access(__s)); }
@@ -674,41 +670,37 @@ inline namespace fundamentals_v1
constexpr const _Tp&
value() const&
{
- return this->_M_is_engaged()
- ? this->_M_get()
- : (__throw_bad_optional_access("Attempt to access value of a "
- "disengaged optional object"),
- this->_M_get());
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ __throw_bad_optional_access("Attempt to access value of a "
+ "disengaged optional object");
}
constexpr _Tp&
value()&
{
- return this->_M_is_engaged()
- ? this->_M_get()
- : (__throw_bad_optional_access("Attempt to access value of a "
- "disengaged optional object"),
- this->_M_get());
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ __throw_bad_optional_access("Attempt to access value of a "
+ "disengaged optional object");
}
constexpr _Tp&&
value()&&
{
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : (__throw_bad_optional_access("Attempt to access value of a "
- "disengaged optional object"),
- std::move(this->_M_get()));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ __throw_bad_optional_access("Attempt to access value of a "
+ "disengaged optional object");
}
constexpr const _Tp&&
value() const&&
{
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : (__throw_bad_optional_access("Attempt to access value of a "
- "disengaged optional object"),
- std::move(this->_M_get()));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ __throw_bad_optional_access("Attempt to access value of a "
+ "disengaged optional object");
}
template<typename _Up>
@@ -719,9 +711,10 @@ inline namespace fundamentals_v1
is_convertible<_Up&&, _Tp>>(),
"Cannot return value");
- return this->_M_is_engaged()
- ? this->_M_get()
- : static_cast<_Tp>(std::forward<_Up>(__u));
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ else
+ return static_cast<_Tp>(std::forward<_Up>(__u));
}
template<typename _Up>
@@ -732,9 +725,10 @@ inline namespace fundamentals_v1
is_convertible<_Up&&, _Tp>>(),
"Cannot return value" );
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : static_cast<_Tp>(std::forward<_Up>(__u));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ else
+ return static_cast<_Tp>(std::forward<_Up>(__u));
}
};
diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional
index 023fe81cae2..fbabb52758e 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -91,12 +91,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ return "bad optional access"; }
};
- void
- __throw_bad_optional_access()
- __attribute__((__noreturn__));
-
// XXX Does not belong here.
- inline void
+ [[__noreturn__]] inline void
__throw_bad_optional_access()
{ _GLIBCXX_THROW_OR_ABORT(bad_optional_access()); }
@@ -943,33 +939,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr const _Tp&
value() const&
{
- return this->_M_is_engaged()
- ? this->_M_get()
- : (__throw_bad_optional_access(), this->_M_get());
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ __throw_bad_optional_access();
}
constexpr _Tp&
value()&
{
- return this->_M_is_engaged()
- ? this->_M_get()
- : (__throw_bad_optional_access(), this->_M_get());
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ __throw_bad_optional_access();
}
constexpr _Tp&&
value()&&
{
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : (__throw_bad_optional_access(), std::move(this->_M_get()));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ __throw_bad_optional_access();
}
constexpr const _Tp&&
value() const&&
{
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : (__throw_bad_optional_access(), std::move(this->_M_get()));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ __throw_bad_optional_access();
}
template<typename _Up>
@@ -979,8 +975,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static_assert(is_copy_constructible_v<_Tp>);
static_assert(is_convertible_v<_Up&&, _Tp>);
- return this->_M_is_engaged()
- ? this->_M_get() : static_cast<_Tp>(std::forward<_Up>(__u));
+ if (this->_M_is_engaged())
+ return this->_M_get();
+ else
+ return static_cast<_Tp>(std::forward<_Up>(__u));
}
template<typename _Up>
@@ -990,9 +988,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static_assert(is_move_constructible_v<_Tp>);
static_assert(is_convertible_v<_Up&&, _Tp>);
- return this->_M_is_engaged()
- ? std::move(this->_M_get())
- : static_cast<_Tp>(std::forward<_Up>(__u));
+ if (this->_M_is_engaged())
+ return std::move(this->_M_get());
+ else
+ return static_cast<_Tp>(std::forward<_Up>(__u));
}
void reset() noexcept { this->_M_reset(); }
reply other threads:[~2021-11-24 11:51 UTC|newest]
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