On 22/10/20 18:59 +0100, Jonathan Wakely wrote:
By moving std::make_obj_using_allocator and the related "utility
functions for uses-allocator construction" to a new header, we can avoid
including the whole of <memory> in <scoped_allocator> and
<memory_resource>.
In order to simplify the implementation of those utility functions they
now use concepts unconditionally. They are no longer defined if
__cpp_concepts is not defined. To simplify the code that uses those
functions I've introduced a __cpp_lib_make_obj_using_allocator feature
test macro (not specified in the standard, which might be an oversight).
That allows the code in <memory_resource> and <scoped_allocator> to
check the feature test macro to decide whether to use the new utilities,
or fall back to the C++17 code.
At the same time, this reshuffles some of the headers included by
<memory> so that they are (mostly?) self-contained. It should no longer
be necessary to include other headers before <bits/shared_ptr.h> when
other parts of the library want to use std::shared_ptr without including
the whole of <memory>.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/bits/shared_ptr.h: Include <iosfwd>.
* include/bits/shared_ptr_base.h: Include required headers here
directly, instead of in <memory>.
* include/bits/uses_allocator_args.h: New file. Move utility
functions for uses-allocator construction from <memory> to here.
Only define the utility functions when concepts are available.
(__cpp_lib_make_obj_using_allocator): Define non-standard
feature test macro.
* include/std/condition_variable: Remove unused headers.
* include/std/future: Likewise.
* include/std/memory: Remove headers that are not needed
directly, and are now inclkuded where they're needed. Include
new <bits/uses_allocator_args.h> header.
* include/std/memory_resource: Include only the necessary
headers. Use new feature test macro to detect support for the
utility functions.
* include/std/scoped_allocator: Likewise.
* include/std/version (__cpp_lib_make_obj_using_allocator):
Define.
The recent changes to reduce includes in <memory_resource> went a bit
too far, and it's possible for std::forward_as_tuple to not be defined
when used.
While doing this, I noticed the problematic calls to forward_as_tuple
were not qualified, so performed unwanted ADL.
Fixed with this patch.
Tested powerpc64le-linux. Committed to trunk.
commit ca021ac617277ba73cb694f8d26ec0f5e1293451
Author: Jonathan Wakely <[email protected]>
Date: Fri Oct 23 00:58:35 2020
libstdc++: Ensure std::forward_as_tuple is defined
The recent changes to reduce includes in <memory_resource> went a bit
too far, and it's possible for std::forward_as_tuple to not be defined
when used.
While doing this, I noticed the problematic calls to forward_as_tuple
were not qualified, so performed unwanted ADL.
libstdc++-v3/ChangeLog:
* include/experimental/memory_resource: Include <tuple>.
(polymorphic_allocator::construct): Qualify forward_as_tuple.
* include/std/memory_resource: Likewise.
diff --git a/libstdc++-v3/include/experimental/memory_resource b/libstdc++-v3/include/experimental/memory_resource
index 1c4de70c533..ca1bad9ecd0 100644
--- a/libstdc++-v3/include/experimental/memory_resource
+++ b/libstdc++-v3/include/experimental/memory_resource
@@ -36,6 +36,7 @@
#include <memory> // align, uses_allocator, __uses_alloc
#include <experimental/utility> // pair, experimental::erased_type
+#include <tuple> // tuple, forward_as_tuple
#include <atomic> // atomic
#include <new> // placement new
#include <cstddef> // max_align_t
@@ -196,8 +197,8 @@ namespace pmr {
construct(pair<_Tp1,_Tp2>* __p, _Up&& __x, _Vp&& __y)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(std::forward<_Up>(__x)),
- forward_as_tuple(std::forward<_Vp>(__y)));
+ std::forward_as_tuple(std::forward<_Up>(__x)),
+ std::forward_as_tuple(std::forward<_Vp>(__y)));
}
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
@@ -205,8 +206,8 @@ namespace pmr {
construct(pair<_Tp1,_Tp2>* __p, const std::pair<_Up, _Vp>& __pr)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(__pr.first),
- forward_as_tuple(__pr.second));
+ std::forward_as_tuple(__pr.first),
+ std::forward_as_tuple(__pr.second));
}
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
@@ -214,8 +215,8 @@ namespace pmr {
construct(pair<_Tp1,_Tp2>* __p, pair<_Up, _Vp>&& __pr)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(std::forward<_Up>(__pr.first)),
- forward_as_tuple(std::forward<_Vp>(__pr.second)));
+ std::forward_as_tuple(std::forward<_Up>(__pr.first)),
+ std::forward_as_tuple(std::forward<_Vp>(__pr.second)));
}
template <typename _Up>
diff --git a/libstdc++-v3/include/std/memory_resource b/libstdc++-v3/include/std/memory_resource
index 350799ee382..40e23a2f9ce 100644
--- a/libstdc++-v3/include/std/memory_resource
+++ b/libstdc++-v3/include/std/memory_resource
@@ -45,6 +45,7 @@
#if ! __cpp_lib_make_obj_using_allocator
# include <utility> // pair, index_sequence
+# include <tuple> // tuple, forward_as_tuple
#endif
namespace std _GLIBCXX_VISIBILITY(default)
@@ -286,8 +287,8 @@ namespace pmr
construct(pair<_Tp1, _Tp2>* __p, _Up&& __x, _Vp&& __y)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(std::forward<_Up>(__x)),
- forward_as_tuple(std::forward<_Vp>(__y)));
+ std::forward_as_tuple(std::forward<_Up>(__x)),
+ std::forward_as_tuple(std::forward<_Vp>(__y)));
}
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
@@ -296,8 +297,8 @@ namespace pmr
construct(pair<_Tp1, _Tp2>* __p, const std::pair<_Up, _Vp>& __pr)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(__pr.first),
- forward_as_tuple(__pr.second));
+ std::forward_as_tuple(__pr.first),
+ std::forward_as_tuple(__pr.second));
}
template<typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
@@ -306,8 +307,8 @@ namespace pmr
construct(pair<_Tp1, _Tp2>* __p, pair<_Up, _Vp>&& __pr)
{
this->construct(__p, piecewise_construct,
- forward_as_tuple(std::forward<_Up>(__pr.first)),
- forward_as_tuple(std::forward<_Vp>(__pr.second)));
+ std::forward_as_tuple(std::forward<_Up>(__pr.first)),
+ std::forward_as_tuple(std::forward<_Vp>(__pr.second)));
}
#else // make_obj_using_allocator
template<typename _Tp1, typename... _Args>
