https://gcc.gnu.org/g:4b55cd211f33200b3c25afe138853351ce4ac4d3
commit r15-2305-g4b55cd211f33200b3c25afe138853351ce4ac4d3
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Jul 23 11:46:05 2024 +0100
libstdc++: Use _M_get() in std::optional internals
Now that _base::_M_get() doesn't check the precondition, we can use
_M_get() instead of operator*() for the internal uses where we've
already checked the precondition holds.
Add a using-declaration so that we don't need to lookup _M_get in the
dependent base class, and make optional<U> a friend so that the
converting constructors and assignment operators can use the parameter's
_M_get member.
libstdc++-v3/ChangeLog:
* include/std/optional (optional): Add using-declaraction for
_Base::_M_get and declare optional<U> as friend.
(optional(const optional<U>&)): Use
_M_get instead of operator*.
(optional(optional<U>&&)): Likewise.
(operator=(const optional<U>&)): Likewise.
(operator=(optional<U>&&)): Likewise.
(and_then, tansform): Likewise.
Diff:
---
libstdc++-v3/include/std/optional | 38 ++++++++++++++++++++------------------
1 file changed, 20 insertions(+), 18 deletions(-)
diff --git a/libstdc++-v3/include/std/optional
b/libstdc++-v3/include/std/optional
index af72004645e2..9ed7ab501402 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -760,7 +760,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
{
if (__t)
- emplace(*__t);
+ emplace(__t._M_get());
}
template<typename _Up,
@@ -773,7 +773,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
{
if (__t)
- emplace(*__t);
+ emplace(__t._M_get());
}
template<typename _Up,
@@ -786,7 +786,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
{
if (__t)
- emplace(std::move(*__t));
+ emplace(std::move(__t._M_get()));
}
template<typename _Up,
@@ -799,7 +799,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
{
if (__t)
- emplace(std::move(*__t));
+ emplace(std::move(__t._M_get()));
}
template<typename... _Args,
@@ -863,9 +863,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (__u)
{
if (this->_M_is_engaged())
- this->_M_get() = *__u;
+ this->_M_get() = __u._M_get();
else
- this->_M_construct(*__u);
+ this->_M_construct(__u._M_get());
}
else
{
@@ -889,9 +889,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (__u)
{
if (this->_M_is_engaged())
- this->_M_get() = std::move(*__u);
+ this->_M_get() = std::move(__u._M_get());
else
- this->_M_construct(std::move(*__u));
+ this->_M_construct(std::move(__u._M_get()));
}
else
{
@@ -1056,7 +1056,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return static_cast<_Tp>(std::forward<_Up>(__u));
}
-#if __cpp_lib_optional >= 202110L
+#if __cpp_lib_optional >= 202110L // C++23
// [optional.monadic]
template<typename _Fn>
@@ -1068,7 +1068,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
"the function passed to std::optional<T>::and_then "
"must return a std::optional");
if (has_value())
- return std::__invoke(std::forward<_Fn>(__f), **this);
+ return std::__invoke(std::forward<_Fn>(__f), _M_get());
else
return _Up();
}
@@ -1082,7 +1082,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
"the function passed to std::optional<T>::and_then "
"must return a std::optional");
if (has_value())
- return std::__invoke(std::forward<_Fn>(__f), **this);
+ return std::__invoke(std::forward<_Fn>(__f), _M_get());
else
return _Up();
}
@@ -1096,7 +1096,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
"the function passed to std::optional<T>::and_then "
"must return a std::optional");
if (has_value())
- return std::__invoke(std::forward<_Fn>(__f), std::move(**this));
+ return std::__invoke(std::forward<_Fn>(__f), std::move(_M_get()));
else
return _Up();
}
@@ -1110,7 +1110,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
"the function passed to std::optional<T>::and_then "
"must return a std::optional");
if (has_value())
- return std::__invoke(std::forward<_Fn>(__f), std::move(**this));
+ return std::__invoke(std::forward<_Fn>(__f), std::move(_M_get()));
else
return _Up();
}
@@ -1121,7 +1121,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
using _Up = remove_cv_t<invoke_result_t<_Fn, _Tp&>>;
if (has_value())
- return optional<_Up>(_Optional_func<_Fn>{__f}, **this);
+ return optional<_Up>(_Optional_func<_Fn>{__f}, _M_get());
else
return optional<_Up>();
}
@@ -1132,7 +1132,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
using _Up = remove_cv_t<invoke_result_t<_Fn, const _Tp&>>;
if (has_value())
- return optional<_Up>(_Optional_func<_Fn>{__f}, **this);
+ return optional<_Up>(_Optional_func<_Fn>{__f}, _M_get());
else
return optional<_Up>();
}
@@ -1143,7 +1143,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
using _Up = remove_cv_t<invoke_result_t<_Fn, _Tp>>;
if (has_value())
- return optional<_Up>(_Optional_func<_Fn>{__f}, std::move(**this));
+ return optional<_Up>(_Optional_func<_Fn>{__f}, std::move(_M_get()));
else
return optional<_Up>();
}
@@ -1154,7 +1154,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
using _Up = remove_cv_t<invoke_result_t<_Fn, const _Tp>>;
if (has_value())
- return optional<_Up>(_Optional_func<_Fn>{__f}, std::move(**this));
+ return optional<_Up>(_Optional_func<_Fn>{__f}, std::move(_M_get()));
else
return optional<_Up>();
}
@@ -1193,9 +1193,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX20_CONSTEXPR void reset() noexcept { this->_M_reset(); }
private:
-#if __cplusplus >= 202002L
+ using _Base::_M_get;
+
template<typename _Up> friend class optional;
+#if __cpp_lib_optional >= 202110L // C++23
template<typename _Fn, typename _Value>
explicit constexpr
optional(_Optional_func<_Fn> __f, _Value&& __v)
