整理

include/boost/align/aligned_allocator_adaptor.hpp

@@ -0,0 +1,170 @@
+/*
+Copyright 2014-2016 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#ifndef BOOST_ALIGN_ALIGNED_ALLOCATOR_ADAPTOR_HPP
+#define BOOST_ALIGN_ALIGNED_ALLOCATOR_ADAPTOR_HPP
+
+#include <boost/align/detail/is_alignment_constant.hpp>
+#include <boost/align/detail/max_align.hpp>
+#include <boost/align/detail/max_size.hpp>
+#include <boost/align/align.hpp>
+#include <boost/align/aligned_allocator_adaptor_forward.hpp>
+#include <boost/align/alignment_of.hpp>
+#include <boost/core/pointer_traits.hpp>
+#include <boost/static_assert.hpp>
+#include <new>
+
+#if !defined(BOOST_NO_CXX11_ALLOCATOR)
+#include <memory>
+#endif
+
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+#include <utility>
+#endif
+
+namespace boost {
+namespace alignment {
+
+template<class Allocator, std::size_t Alignment>
+class aligned_allocator_adaptor
+    : public Allocator {
+    BOOST_STATIC_ASSERT(detail::is_alignment_constant<Alignment>::value);
+
+#if !defined(BOOST_NO_CXX11_ALLOCATOR)
+    typedef std::allocator_traits<Allocator> traits;
+    typedef typename traits::template rebind_alloc<char> char_alloc;
+    typedef typename traits::template rebind_traits<char> char_traits;
+    typedef typename char_traits::pointer char_ptr;
+#else
+    typedef typename Allocator::template rebind<char>::other char_alloc;
+    typedef typename char_alloc::pointer char_ptr;
+#endif
+
+public:
+    typedef typename Allocator::value_type value_type;
+    typedef value_type* pointer;
+    typedef const value_type* const_pointer;
+    typedef void* void_pointer;
+    typedef const void* const_void_pointer;
+    typedef std::size_t size_type;
+    typedef std::ptrdiff_t difference_type;
+
+private:
+    template<class U>
+    struct min_align {
+        enum {
+            value = detail::max_size<Alignment,
+                detail::max_align<U, char_ptr>::value>::value
+        };
+    };
+
+public:
+    template<class U>
+    struct rebind {
+#if !defined(BOOST_NO_CXX11_ALLOCATOR)
+        typedef aligned_allocator_adaptor<typename traits::template
+            rebind_alloc<U>, Alignment> other;
+#else
+        typedef aligned_allocator_adaptor<typename Allocator::template
+            rebind<U>::other, Alignment> other;
+#endif
+    };
+
+    aligned_allocator_adaptor()
+        : Allocator() { }
+
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+    template<class A>
+    explicit aligned_allocator_adaptor(A&& alloc) BOOST_NOEXCEPT
+        : Allocator(std::forward<A>(alloc)) { }
+#else
+    template<class A>
+    explicit aligned_allocator_adaptor(const A& alloc) BOOST_NOEXCEPT
+        : Allocator(alloc) { }
+#endif
+
+    template<class U>
+    aligned_allocator_adaptor(const aligned_allocator_adaptor<U,
+        Alignment>& other) BOOST_NOEXCEPT
+        : Allocator(other.base()) { }
+
+    Allocator& base() BOOST_NOEXCEPT {
+        return static_cast<Allocator&>(*this);
+    }
+
+    const Allocator& base() const BOOST_NOEXCEPT {
+        return static_cast<const Allocator&>(*this);
+    }
+
+    pointer allocate(size_type size) {
+        enum {
+            m = min_align<value_type>::value
+        };
+        std::size_t s = size * sizeof(value_type);
+        std::size_t n = s + m - 1;
+        char_alloc a(base());
+        char_ptr p = a.allocate(sizeof p + n);
+        void* r = boost::to_address(p) + sizeof p;
+        (void)boost::alignment::align(m, s, r, n);
+        ::new(static_cast<void*>(static_cast<char_ptr*>(r) - 1)) char_ptr(p);
+        return static_cast<pointer>(r);
+    }
+
+    pointer allocate(size_type size, const_void_pointer hint) {
+        enum {
+            m = min_align<value_type>::value
+        };
+        std::size_t s = size * sizeof(value_type);
+        std::size_t n = s + m - 1;
+        char_ptr h = char_ptr();
+        if (hint) {
+            h = *(static_cast<const char_ptr*>(hint) - 1);
+        }
+        char_alloc a(base());
+#if !defined(BOOST_NO_CXX11_ALLOCATOR)
+        char_ptr p = char_traits::allocate(a, sizeof p + n, h);
+#else
+        char_ptr p = a.allocate(sizeof p + n, h);
+#endif
+        void* r = boost::to_address(p) + sizeof p;
+        (void)boost::alignment::align(m, s, r, n);
+        ::new(static_cast<void*>(static_cast<char_ptr*>(r) - 1)) char_ptr(p);
+        return static_cast<pointer>(r);
+    }
+
+    void deallocate(pointer ptr, size_type size) {
+        enum {
+            m = min_align<value_type>::value
+        };
+        char_ptr* p = reinterpret_cast<char_ptr*>(ptr) - 1;
+        char_ptr r = *p;
+        p->~char_ptr();
+        char_alloc a(base());
+        a.deallocate(r, sizeof r + size * sizeof(value_type) + m - 1);
+    }
+};
+
+template<class A, class B, std::size_t Alignment>
+inline bool
+operator==(const aligned_allocator_adaptor<A, Alignment>& a,
+    const aligned_allocator_adaptor<B, Alignment>& b) BOOST_NOEXCEPT
+{
+    return a.base() == b.base();
+}
+
+template<class A, class B, std::size_t Alignment>
+inline bool
+operator!=(const aligned_allocator_adaptor<A, Alignment>& a,
+    const aligned_allocator_adaptor<B, Alignment>& b) BOOST_NOEXCEPT
+{
+    return !(a == b);
+}
+
+} /* alignment */
+} /* boost */
+
+#endif