On 03/08/16 20:11 +0100, Jonathan Wakely wrote:
Another feature we already support, so just define the macro.* include/bits/shared_ptr_base.h (__cpp_lib_enable_shared_from_this): Define feature-test macro. * testsuite/20_util/enable_shared_from_this/members/reinit.cc: Test for the macro. Tested x86_64-linux, committed to trunk.
I realised we don't actually implement the whole feature, because we don't have the new weak_from_this() members (careless of me to forget the contents of my own proposal!) This adds them for C++17, or gnu++1*, and only defines the feature-test macro when those members are present. Tested powerpc64-linux, committed to trunk.
commit 7c1f28db94c3cb1a28dba4efd0c648bc6c6bb329 Author: Jonathan Wakely <[email protected]> Date: Thu Aug 4 13:04:14 2016 +0100 Define std::enable_shared_from_this::weak_from_this * testsuite/20_util/enable_shared_from_this/members/reinit.cc: Use effective target not dg-options. Move check for feature-test macro to: * testsuite/20_util/enable_shared_from_this/members/weak_from_this.cc: New test. diff --git a/libstdc++-v3/include/bits/shared_ptr.h b/libstdc++-v3/include/bits/shared_ptr.h index 483c2bc..747b09a 100644 --- a/libstdc++-v3/include/bits/shared_ptr.h +++ b/libstdc++-v3/include/bits/shared_ptr.h @@ -586,6 +586,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION shared_from_this() const { return shared_ptr<const _Tp>(this->_M_weak_this); } +#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 +#define __cpp_lib_enable_shared_from_this 201603 + weak_ptr<_Tp> + weak_from_this() + { return this->_M_weak_this; } + + weak_ptr<const _Tp> + weak_from_this() const + { return this->_M_weak_this; } +#endif + private: template<typename _Tp1> void diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h index 2698ba4..787dc9b 100644 --- a/libstdc++-v3/include/bits/shared_ptr_base.h +++ b/libstdc++-v3/include/bits/shared_ptr_base.h @@ -1472,7 +1472,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept { -#define __cpp_lib_enable_shared_from_this 201603 if (use_count() == 0) { _M_ptr = __ptr; @@ -1557,6 +1556,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION shared_from_this() const { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); } +#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 + __weak_ptr<_Tp, _Lp> + weak_from_this() + { return this->_M_weak_this; } + + __weak_ptr<const _Tp, _Lp> + weak_from_this() const + { return this->_M_weak_this; } +#endif + private: template<typename _Tp1> void diff --git a/libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/reinit.cc b/libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/reinit.cc index 1cf9148..3209f87 100644 --- a/libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/reinit.cc +++ b/libstdc++-v3/testsuite/20_util/enable_shared_from_this/members/reinit.cc @@ -15,15 +15,11 @@ // with this library; see the file COPYING3. If not see // <http://www.gnu.org/licenses/>. -// { dg-options "-std=gnu++11" } +// { dg-do run { target c++11 } } #include <memory> #include <testsuite_hooks.h> -#if __cpp_lib_enable_shared_from_this < 201603 -# error "__cpp_lib_enable_shared_from_this < 201603" -#endif - struct X : public std::enable_shared_from_this<X> { }; bool
