PR libstdc++/55043

[pf3gnuchains/gcc-fork.git] / libstdc++-v3 / include / bits / alloc_traits.h

diff --git a/libstdc++-v3/include/bits/alloc_traits.h b/libstdc++-v3/include/bits/alloc_traits.h
index 3b12981..bfa50de 100644 (file)
--- a/libstdc++-v3/include/bits/alloc_traits.h
+++ b/libstdc++-v3/include/bits/alloc_traits.h
@@ -1,6 +1,6 @@
 // Allocator traits -*- C++ -*-
 
-// Copyright (C) 2011, 2012 Free Software Foundation, Inc.
+// Copyright (C) 2011, 2012, 2013 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -39,6 +39,9 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+  template<typename _Tp>
+    class allocator;
+
   template<typename _Alloc, typename _Tp>
     class __alloctr_rebind_helper
     {
@@ -254,7 +257,8 @@ _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_swap,
 
       template<typename _Tp, typename... _Args>
        static typename
-               enable_if<!__construct_helper<_Tp, _Args...>::value, void>::type
+       enable_if<__and_<__not_<__construct_helper<_Tp, _Args...>>,
+                        is_constructible<_Tp, _Args...>>::value, void>::type
                _S_construct(_Alloc&, _Tp* __p, _Args&&... __args)
        { ::new((void*)__p) _Tp(std::forward<_Args>(__args)...); }
 
@@ -386,7 +390,8 @@ _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_swap,
        *  arguments @a __args...
       */
       template<typename _Tp, typename... _Args>
-       static void construct(_Alloc& __a, _Tp* __p, _Args&&... __args)
+       static auto construct(_Alloc& __a, _Tp* __p, _Args&&... __args)
+       -> decltype(_S_construct(__a, __p, std::forward<_Args>(__args)...))
        { _S_construct(__a, __p, std::forward<_Args>(__args)...); }
 
       /**
@@ -506,6 +511,56 @@ _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_swap,
       __do_alloc_on_swap(__one, __two, __pocs());
     }
 
+  template<typename _Alloc>
+    class __is_copy_insertable_impl
+    {
+      typedef allocator_traits<_Alloc> _Traits;
+
+      template<typename _Up, typename
+              = decltype(_Traits::construct(std::declval<_Alloc&>(),
+                                            std::declval<_Up*>(),
+                                            std::declval<const _Up&>()))>
+       static true_type
+       _M_select(int);
+
+      template<typename _Up>
+       static false_type
+       _M_select(...);
+
+    public:
+      typedef decltype(_M_select<typename _Alloc::value_type>(0)) type;
+    };
+
+  // true if _Alloc::value_type is CopyInsertable into containers using _Alloc
+  template<typename _Alloc>
+    struct __is_copy_insertable
+    : __is_copy_insertable_impl<_Alloc>::type
+    { };
+
+  // std::allocator<_Tp> just requires CopyConstructible
+  template<typename _Tp>
+    struct __is_copy_insertable<allocator<_Tp>>
+    : is_copy_constructible<_Tp>
+    { };
+
+  // Used to allow copy construction of unordered containers
+  template<bool> struct __allow_copy_cons { };
+
+  // Used to delete copy constructor of unordered containers
+  template<>
+    struct __allow_copy_cons<false>
+    {
+      __allow_copy_cons() = default;
+      __allow_copy_cons(const __allow_copy_cons&) = delete;
+      __allow_copy_cons(__allow_copy_cons&&) = default;
+      __allow_copy_cons& operator=(const __allow_copy_cons&) = default;
+      __allow_copy_cons& operator=(__allow_copy_cons&&) = default;
+    };
+
+  template<typename _Alloc>
+    using __check_copy_constructible
+      = __allow_copy_cons<__is_copy_insertable<_Alloc>::value>;
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std