Chris@101: /* Copyright 2003-2013 Joaquin M Lopez Munoz.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  * (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  * http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  *
Chris@16:  * See Boost website at http://www.boost.org/
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP
Chris@16: #define BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP
Chris@16: 
Chris@16: #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <cstddef>
Chris@16: #include <memory>
Chris@16: #include <new>
Chris@16: 
Chris@16: namespace boost{
Chris@16: 
Chris@16: namespace detail{
Chris@16: 
Chris@16: /* Allocator adaption layer. Some stdlibs provide allocators without rebind
Chris@16:  * and template ctors. These facilities are simulated with the external
Chris@16:  * template class rebind_to and the aid of partial_std_allocator_wrapper.
Chris@16:  */
Chris@16: 
Chris@16: namespace allocator{
Chris@16: 
Chris@16: /* partial_std_allocator_wrapper inherits the functionality of a std
Chris@16:  * allocator while providing a templatized ctor and other bits missing
Chris@16:  * in some stdlib implementation or another.
Chris@16:  */
Chris@16: 
Chris@16: template<typename Type>
Chris@16: class partial_std_allocator_wrapper:public std::allocator<Type>
Chris@16: {
Chris@16: public:
Chris@16:   /* Oddly enough, STLport does not define std::allocator<void>::value_type
Chris@16:    * when configured to work without partial template specialization.
Chris@16:    * No harm in supplying the definition here unconditionally.
Chris@16:    */
Chris@16: 
Chris@16:   typedef Type value_type;
Chris@16: 
Chris@16:   partial_std_allocator_wrapper(){};
Chris@16: 
Chris@16:   template<typename Other>
Chris@16:   partial_std_allocator_wrapper(const partial_std_allocator_wrapper<Other>&){}
Chris@16: 
Chris@16:   partial_std_allocator_wrapper(const std::allocator<Type>& x):
Chris@16:     std::allocator<Type>(x)
Chris@16:   {
Chris@16:   };
Chris@16: 
Chris@16: #if defined(BOOST_DINKUMWARE_STDLIB)
Chris@16:   /* Dinkumware guys didn't provide a means to call allocate() without
Chris@16:    * supplying a hint, in disagreement with the standard.
Chris@16:    */
Chris@16: 
Chris@16:   Type* allocate(std::size_t n,const void* hint=0)
Chris@16:   {
Chris@16:     std::allocator<Type>& a=*this;
Chris@16:     return a.allocate(n,hint);
Chris@16:   }
Chris@16: #endif
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: /* Detects whether a given allocator belongs to a defective stdlib not
Chris@16:  * having the required member templates.
Chris@16:  * Note that it does not suffice to check the Boost.Config stdlib
Chris@16:  * macros, as the user might have passed a custom, compliant allocator.
Chris@16:  * The checks also considers partial_std_allocator_wrapper to be
Chris@16:  * a standard defective allocator.
Chris@16:  */
Chris@16: 
Chris@16: #if defined(BOOST_NO_STD_ALLOCATOR)&&\
Chris@16:   (defined(BOOST_HAS_PARTIAL_STD_ALLOCATOR)||defined(BOOST_DINKUMWARE_STDLIB))
Chris@16: 
Chris@16: template<typename Allocator>
Chris@16: struct is_partial_std_allocator
Chris@16: {
Chris@16:   BOOST_STATIC_CONSTANT(bool,
Chris@16:     value=
Chris@16:       (is_same<
Chris@16:         std::allocator<BOOST_DEDUCED_TYPENAME Allocator::value_type>,
Chris@16:         Allocator
Chris@16:       >::value)||
Chris@16:       (is_same<
Chris@16:         partial_std_allocator_wrapper<
Chris@16:           BOOST_DEDUCED_TYPENAME Allocator::value_type>,
Chris@16:         Allocator
Chris@16:       >::value));
Chris@16: };
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: template<typename Allocator>
Chris@16: struct is_partial_std_allocator
Chris@16: {
Chris@16:   BOOST_STATIC_CONSTANT(bool,value=false);
Chris@16: };
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: /* rebind operations for defective std allocators */
Chris@16: 
Chris@16: template<typename Allocator,typename Type>
Chris@16: struct partial_std_allocator_rebind_to
Chris@16: {
Chris@16:   typedef partial_std_allocator_wrapper<Type> type;
Chris@16: };
Chris@16: 
Chris@16: /* rebind operation in all other cases */
Chris@16: 
Chris@16: template<typename Allocator>
Chris@16: struct rebinder
Chris@16: {
Chris@16:   template<typename Type>
Chris@16:   struct result
Chris@16:   {
Chris@16:       typedef typename Allocator::BOOST_NESTED_TEMPLATE 
Chris@16:           rebind<Type>::other other;
Chris@16:   };
Chris@16: };
Chris@16: 
Chris@16: template<typename Allocator,typename Type>
Chris@16: struct compliant_allocator_rebind_to
Chris@16: {
Chris@16:   typedef typename rebinder<Allocator>::
Chris@16:       BOOST_NESTED_TEMPLATE result<Type>::other type;
Chris@16: };
Chris@16: 
Chris@16: /* rebind front-end */
Chris@16: 
Chris@16: template<typename Allocator,typename Type>
Chris@16: struct rebind_to:
Chris@16:   mpl::eval_if_c<
Chris@16:     is_partial_std_allocator<Allocator>::value,
Chris@16:     partial_std_allocator_rebind_to<Allocator,Type>,
Chris@16:     compliant_allocator_rebind_to<Allocator,Type>
Chris@16:   >
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: /* allocator-independent versions of construct and destroy */
Chris@16: 
Chris@16: template<typename Type>
Chris@16: void construct(void* p,const Type& t)
Chris@16: {
Chris@16:   new (p) Type(t);
Chris@16: }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500))
Chris@16: /* MSVC++ issues spurious warnings about unreferencend formal parameters
Chris@16:  * in destroy<Type> when Type is a class with trivial dtor.
Chris@16:  */
Chris@16: 
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable:4100)  
Chris@16: #endif
Chris@16: 
Chris@16: template<typename Type>
Chris@16: void destroy(const Type* p)
Chris@16: {
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(__SUNPRO_CC,BOOST_TESTED_AT(0x590))
Chris@16:   const_cast<Type*>(p)->~Type();
Chris@16: #else
Chris@16:   p->~Type();
Chris@16: #endif
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500))
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: } /* namespace boost::detail::allocator */
Chris@16: 
Chris@16: } /* namespace boost::detail */
Chris@16: 
Chris@16: } /* namespace boost */
Chris@16: 
Chris@16: #endif