Enforce LWG DR 2566 requirement for container adaptors

Although there is no good use for stack<int, deque<double>> or similar
types with a mismatched value_type, it's possible somebody is doing that
and getting away with it currently. This patch only enforces the new
requirement for C++17 and later. During stage 1 we should consider
enforcing it for C++11 and C++14.

	* doc/xml/manual/intro.xml: Document LWG 2566 status.
	* include/bits/stl_queue.h (queue, priority_queue): Add static
	assertions to enforce LWG 2566 requirement on value_type.
	* include/bits/stl_stack.h (stack): Likewise.

From-SVN: r268877
This commit is contained in:
Jonathan Wakely 2019-02-14 14:10:12 +00:00 committed by Jonathan Wakely
parent affd7d477a
commit 1138a19dfe
4 changed files with 45 additions and 9 deletions

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@ -1,5 +1,10 @@
2019-02-14 Jonathan Wakely <jwakely@redhat.com>
* doc/xml/manual/intro.xml: Document LWG 2566 status.
* include/bits/stl_queue.h (queue, priority_queue): Add static
assertions to enforce LWG 2566 requirement on value_type.
* include/bits/stl_stack.h (stack): Likewise.
PR middle-end/89303
* testsuite/20_util/enable_shared_from_this/89303.cc: New test.

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@ -1120,11 +1120,18 @@ requirements of the license of GCC.
ill-formed.
</para></listitem></varlistentry>
<varlistentry xml:id="manual.bugs.dr2537"><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="&DR;#2537">2537</link>:
<emphasis>Requirements on the first template parameter of container adaptors
</emphasis>
</term>
<listitem><para>Add static assertions to enforce the requirement.
</para></listitem></varlistentry>
<varlistentry xml:id="manual.bugs.dr2583"><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="&DR;#2583">2583</link>:
<emphasis>There is no way to supply an allocator for <code>basic_string(str, pos)</code>
</emphasis>
</term>
<listitem><para>Add new constructor
<listitem><para>Add new constructor.
</para></listitem></varlistentry>
<varlistentry xml:id="manual.bugs.dr2684"><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="&DR;#2684">2684</link>:

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@ -118,7 +118,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Alloc>
using _Uses = typename
enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
#endif
#if __cplusplus >= 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2566. Requirements on the first template parameter of container
// adaptors
static_assert(is_same<_Tp, typename _Sequence::value_type>::value,
"value_type must be the same as the underlying container");
#endif // C++17
#endif // C++11
public:
typedef typename _Sequence::value_type value_type;
@ -451,17 +459,25 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Alloc>
using _Uses = typename
enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
#endif
#if __cplusplus >= 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2566. Requirements on the first template parameter of container
// adaptors
static_assert(is_same<_Tp, typename _Sequence::value_type>::value,
"value_type must be the same as the underlying container");
#endif // C++17
#endif // C++11
public:
typedef typename _Sequence::value_type value_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 2684. priority_queue lacking comparator typedef
typedef _Compare value_compare;
typedef _Compare value_compare;
protected:
// See queue::c for notes on these names.

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@ -120,7 +120,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Alloc>
using _Uses = typename
enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
#endif
#if __cplusplus >= 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2566. Requirements on the first template parameter of container
// adaptors
static_assert(is_same<_Tp, typename _Sequence::value_type>::value,
"value_type must be the same as the underlying container");
#endif // C++17
#endif // C++11
public:
typedef typename _Sequence::value_type value_type;