Implement LWG#2921 and LWG#2976 - removing allocator support from packaged_task.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@319080 91177308-0d34-0410-b5e6-96231b3b80d8

include/future

@@ -328,8 +328,6 @@ public:
     packaged_task() noexcept;
     template <class F>
         explicit packaged_task(F&& f);
-    template <class F, class Allocator>
-        packaged_task(allocator_arg_t, const Allocator& a, F&& f);
     ~packaged_task();
 
     // no copy
@@ -356,8 +354,6 @@ public:
 template <class R>
   void swap(packaged_task<R(ArgTypes...)&, packaged_task<R(ArgTypes...)>&) noexcept;
 
-template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>;
-
 }  // std
 
 */
@@ -2028,19 +2024,6 @@ public:
              >
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename decay<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-              >
-        _LIBCPP_INLINE_VISIBILITY
-        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
-             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
-               __p_(allocator_arg, __a) {}
     // ~packaged_task() = default;
 
     // no copy
@@ -2157,19 +2140,6 @@ public:
               >
         _LIBCPP_INLINE_VISIBILITY
         explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename decay<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-              >    
-        _LIBCPP_INLINE_VISIBILITY
-        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
-             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
-               __p_(allocator_arg, __a) {}
     // ~packaged_task() = default;
 
     // no copy
@@ -2271,10 +2241,6 @@ swap(packaged_task<_Callable>& __x, packaged_task<_Callable>& __y) _NOEXCEPT
     __x.swap(__y);
 }
 
-template <class _Callable, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<packaged_task<_Callable>, _Alloc>
-    : public true_type {};
-
 template <class _Rp, class _Fp>
 future<_Rp>
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

test/std/thread/futures/futures.task/futures.task.members/ctor2.fail.cpp

@@ -1,34 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// UNSUPPORTED: libcpp-has-no-threads
-// UNSUPPORTED: c++98, c++03
-
-// <future>
-
-// class packaged_task<R(ArgTypes...)>
-// template <class F, class Allocator>
-//   packaged_task(allocator_arg_t, const Allocator& a, F&& f);
-// These constructors shall not participate in overload resolution if
-//    decay<F>::type is the same type as std::packaged_task<R(ArgTypes...)>.
-
-#include <future>
-#include <cassert>
-
-#include "test_allocator.h"
-
-struct A {};
-typedef std::packaged_task<A(int, char)> PT;
-typedef volatile std::packaged_task<A(int, char)> VPT;
-
-int main()
-{
-    PT p { std::allocator_arg_t{}, test_allocator<A>{}, VPT {}}; // expected-error {{no matching constructor for initialization of 'PT' (aka 'packaged_task<A (int, char)>')}}
-    // expected-note-re@future:* 1 {{candidate template ignored: {{(disabled by 'enable_if')|(requirement '.*' was not satisfied)}}}}
-}

test/std/thread/futures/futures.task/futures.task.members/ctor_func_alloc.pass.cpp

@@ -16,9 +16,6 @@
 
 // class packaged_task<R(ArgTypes...)>
 
-// template <class F, class Allocator>
-//     explicit packaged_task(allocator_arg_t, const Allocator& a, F&& f);
-
 #include <future>
 #include <cassert>
 

www/cxx1z_status.html

@@ -487,7 +487,7 @@
 	<tr><td><a href="https://wg21.link/LWG2905">2905</a></td><td>is_constructible_v&lt;unique_ptr&lt;P, D&gt;, P, D const &amp;&gt; should be false when D is not copy constructible</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2908">2908</a></td><td>The less-than operator for shared pointers could do more</td><td>Kona</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2911">2911</a></td><td>An is_aggregate type trait is needed</td><td>Kona</td><td>Complete</td></tr>
-	<tr><td><a href="https://wg21.link/LWG2921">2921</a></td><td>packaged_task and type-erased allocators</td><td>Kona</td><td></td></tr>
+	<tr><td><a href="https://wg21.link/LWG2921">2921</a></td><td>packaged_task and type-erased allocators</td><td>Kona</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2934">2934</a></td><td>optional&lt;const T&gt; doesn't compare with T</td><td>Kona</td><td>Complete</td></tr>
  	<tr><td></td><td></td><td></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2901">2901</a></td><td>Variants cannot properly support allocators</td><td>Toronto</td><td>Complete</td></tr>

www/cxx2a_status.html

@@ -114,7 +114,7 @@
 	<tr><td><a href="https://wg21.link/LWG2964">2964</a></td><td>Apparently redundant requirement for dynamic_pointer_cast</td><td>Albuquerque</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2965">2965</a></td><td>Non-existing path::native_string() in filesystem_error::what() specification</td><td>Albuquerque</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2972">2972</a></td><td>What is is_trivially_destructible_v<int>?</td><td>Albuquerque</td><td>Complete</td></tr>
-	<tr><td><a href="https://wg21.link/LWG2976">2976</a></td><td>Dangling uses_allocator specialization for packaged_task</td><td>Albuquerque</td><td></td></tr>
+	<tr><td><a href="https://wg21.link/LWG2976">2976</a></td><td>Dangling uses_allocator specialization for packaged_task</td><td>Albuquerque</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2977">2977</a></td><td>unordered_meow::merge() has incorrect Throws: clause</td><td>Albuquerque</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2978">2978</a></td><td>Hash support for pmr::string and friends</td><td>Albuquerque</td><td></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2979">2979</a></td><td>aligned_union should require complete object types</td><td>Albuquerque</td><td>Complete</td></tr>