From fc82a4b926b44b0c72a21c3770c3b007445439c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joaqu=C3=ADn=20M=2E=20L=C3=B3pez=20Mu=C3=B1oz?=
 <joaquin@tid.es>
Date: Wed, 2 Jun 2004 14:35:30 +0000
Subject: [PATCH] moved from boost/multi_index/detail

[SVN r23004]
---
 include/boost/detail/allocator.hpp | 178 +++++++++++++++++++++++++++++
 1 file changed, 178 insertions(+)
 create mode 100644 include/boost/detail/allocator.hpp

diff --git a/include/boost/detail/allocator.hpp b/include/boost/detail/allocator.hpp
new file mode 100644
index 0000000..e2cb07d
--- /dev/null
+++ b/include/boost/detail/allocator.hpp
@@ -0,0 +1,178 @@
+/* Copyright 2003-2004 Joaquín M López Muñoz.
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt)
+ *
+ * See Boost website at http://www.boost.org/
+ */
+
+#ifndef BOOST_DETAIL_ALLOCATOR_HPP
+#define BOOST_DETAIL_ALLOCATOR_HPP
+
+#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
+#include <boost/detail/workaround.hpp>
+#include <boost/mpl/aux_/msvc_never_true.hpp>
+#include <boost/mpl/apply_if.hpp>
+#include <boost/type_traits/is_base_and_derived.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <cstddef>
+#include <memory>
+#include <new>
+
+namespace boost{
+
+namespace detail{
+
+/* Allocator adaption layer. Some stdlibs provide allocators without rebind
+ * and template ctors. These facilities are simulated with the external
+ * template class rebind_to and the aid of partial_std_allocator_wrapper.
+ */
+
+namespace allocator{
+
+/* Detects whether a given allocator belongs to a defective stdlib not
+ * having the required member templates.
+ * Note that it does not suffice to check the Boost.Config stdlib
+ * macros, as the user might have passed a custom, compliant allocator.
+ * The checks also considers partial_std_allocator_wrapper to be
+ * a standard defective allocator.
+ */
+
+#if defined(BOOST_NO_STD_ALLOCATOR)&&\
+  (defined(BOOST_HAS_PARTIAL_STD_ALLOCATOR)||defined(BOOST_DINKUMWARE_STDLIB))
+
+template<typename Allocator>
+struct is_partial_std_allocator
+{
+  BOOST_STATIC_CONSTANT(bool,
+    value=
+      (is_same<
+        std::allocator<BOOST_DEDUCED_TYPENAME Allocator::value_type>,
+        Allocator
+      >::value)||
+      (is_base_and_derived<
+        std::allocator<BOOST_DEDUCED_TYPENAME Allocator::value_type>,
+        Allocator
+      >::value));
+};
+
+#else
+
+template<typename Allocator>
+struct is_partial_std_allocator
+{
+  BOOST_STATIC_CONSTANT(bool,value=false);
+};
+
+#endif
+
+/* partial_std_allocator_wrapper inherits the functionality of a std
+ * allocator while providing a templatized ctor.
+ */
+
+template<typename Type>
+class partial_std_allocator_wrapper:public std::allocator<Type>
+{
+public:
+  partial_std_allocator_wrapper(){};
+
+  template<typename Other>
+  partial_std_allocator_wrapper(const partial_std_allocator_wrapper<Other>&){}
+
+#if defined(BOOST_DINKUMWARE_STDLIB)
+  /* Dinkumware guys didn't provide a means to call allocate() without
+   * supplying a hint, in disagreement with the standard.
+   */
+
+  Type* allocate(std::size_t n,const void* hint=0)
+  {
+    std::allocator<Type>& a=*this;
+    return a.allocate(n,hint);
+  }
+#endif
+
+};
+
+/* rebind operations for defective std allocators */
+
+template<typename Allocator,typename Type>
+struct partial_std_allocator_rebind_to
+{
+  typedef partial_std_allocator_wrapper<Type> type;
+};
+
+/* rebind operation in all other cases */
+
+#if BOOST_WORKAROUND(BOOST_MSVC,<1300)
+/* Workaround for a problem in MSVC with dependent template typedefs
+ * when doing rebinding of allocators.
+ * Modeled after <boost/mpl/aux_/msvc_dtw.hpp> (thanks, Aleksey!)
+ */
+
+template<typename Allocator>
+struct rebinder
+{
+  template<bool> struct fake_allocator:Allocator{};
+  template<> struct fake_allocator<true>
+  {
+    template<typename Type> struct rebind{};
+  };
+
+  template<typename Type>
+  struct result:
+    fake_allocator<mpl::aux::msvc_never_true<Allocator>::value>::
+      template rebind<Type>
+  {
+  };
+};
+#else
+template<typename Allocator>
+struct rebinder
+{
+  template<typename Type>
+  struct result:Allocator::BOOST_NESTED_TEMPLATE rebind<Type>
+  {
+  };
+};
+#endif
+
+template<typename Allocator,typename Type>
+struct compliant_allocator_rebind_to
+{
+  typedef typename rebinder<Allocator>::
+      BOOST_NESTED_TEMPLATE result<Type>::other type;
+};
+
+/* rebind front-end */
+
+template<typename Allocator,typename Type>
+struct rebind_to:
+  mpl::apply_if_c<
+    is_partial_std_allocator<Allocator>::value,
+    partial_std_allocator_rebind_to<Allocator,Type>,
+    compliant_allocator_rebind_to<Allocator,Type>
+  >
+{
+};
+
+/* allocator-independent versions of construct and destroy */
+
+template<typename Type>
+void construct(void* p,const Type& t)
+{
+  new (p) Type(t);
+}
+
+template<typename Type>
+void destroy(const Type* p)
+{
+  p->~Type();
+}
+
+} /* namespace boost::detail::allocator */
+
+} /* namespace boost::detail */
+
+} /* namespace boost */
+
+#endif