diff options
Diffstat (limited to 'libstdc++-v3/include/bits/ptr_traits.h')
| -rw-r--r-- | libstdc++-v3/include/bits/ptr_traits.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/libstdc++-v3/include/bits/ptr_traits.h b/libstdc++-v3/include/bits/ptr_traits.h new file mode 100644 index 00000000000..342db12aff8 --- /dev/null +++ b/libstdc++-v3/include/bits/ptr_traits.h @@ -0,0 +1,222 @@ +// Pointer Traits -*- C++ -*- + +// Copyright (C) 2011 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 +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// Under Section 7 of GPL version 3, you are granted additional +// permissions described in the GCC Runtime Library Exception, version +// 3.1, as published by the Free Software Foundation. + +// You should have received a copy of the GNU General Public License and +// a copy of the GCC Runtime Library Exception along with this program; +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +// <http://www.gnu.org/licenses/>. + +/** @file bits/ptr_traits.h + * This is an internal header file, included by other library headers. + * Do not attempt to use it directly. @headername{memory} + */ + +#ifndef _PTR_TRAITS_H +#define _PTR_TRAITS_H 1 + +#ifdef __GXX_EXPERIMENTAL_CXX0X__ + +#include <type_traits> // For _GLIBCXX_HAS_NESTED_TYPE + +namespace std _GLIBCXX_VISIBILITY(default) +{ +_GLIBCXX_BEGIN_NAMESPACE_VERSION + +_GLIBCXX_HAS_NESTED_TYPE(element_type) +_GLIBCXX_HAS_NESTED_TYPE(difference_type) + + template<typename _Tp, bool = __has_element_type<_Tp>::value> + struct __ptrtr_elt_type; + + template<typename _Tp> + struct __ptrtr_elt_type<_Tp, true> + { + typedef typename _Tp::element_type __type; + }; + + template<template<typename, typename...> class _SomePtr, typename _Tp, + typename... _Args> + struct __ptrtr_elt_type<_SomePtr<_Tp, _Args...>, false> + { + typedef _Tp __type; + }; + + template<typename _Tp, bool = __has_difference_type<_Tp>::value> + struct __ptrtr_diff_type + { + typedef typename _Tp::difference_type __type; + }; + + template<typename _Tp> + struct __ptrtr_diff_type<_Tp, false> + { + typedef ptrdiff_t __type; + }; + + template<typename _Ptr, typename _Up> + class __ptrtr_rebind_helper + { + template<typename _Ptr2, typename _Up2> + static constexpr bool + _S_chk(typename _Ptr2::template rebind<_Up2>*) + { return true; } + + template<typename, typename> + static constexpr bool + _S_chk(...) + { return false; } + + public: + static const bool __value = _S_chk<_Ptr, _Up>(nullptr); + }; + + // hack to use _Tp::__rebind<_Up>::__type instead if that exists + template<typename _Ptr, typename _Up> + class __ptrtr_rebind_helper2 + { + template<typename _Ptr2, typename _Up2> + static constexpr bool + _S_chk(typename _Ptr2::template __rebind<_Up2>::__type*) + { return true; } + + template<typename, typename> + static constexpr bool + _S_chk(...) + { return false; } + + public: + static const bool __value = _S_chk<_Ptr, _Up>(nullptr); + }; + + /* TODO: remove second bool when alias templates are supported */ + template<typename _Tp, typename _Up, + bool = __ptrtr_rebind_helper<_Tp, _Up>::value, + bool = __ptrtr_rebind_helper2<_Tp, _Up>::value> + struct __ptrtr_rebind; + + template<typename _Tp, typename _Up, bool _B2> + struct __ptrtr_rebind<_Tp, _Up, true, _B2> + { + typedef typename _Tp::template rebind<_Up> __type; + }; + + /* TODO: remove this when alias templates are supported */ + template<typename _Tp, typename _Up> + struct __ptrtr_rebind<_Tp, _Up, false, true> + { + typedef typename _Tp::template __rebind<_Up>::__type __type; + }; + + template<template<typename, typename...> class _SomePtr, typename _Up, + typename _Tp, typename... _Args> + struct __ptrtr_rebind<_SomePtr<_Tp, _Args...>, _Up, false, false> + { + typedef _SomePtr<_Up, _Args...> __type; + }; + + template<typename _Tp, typename = typename remove_cv<_Tp>::type> + struct __ptrtr_not_void + { + typedef _Tp __type; + }; + + template<typename _Tp> + struct __ptrtr_not_void<_Tp, void> + { + struct __type { }; + }; + + template<typename _Ptr> + class __ptrtr_pointer_to + { + typedef typename __ptrtr_elt_type<_Ptr>::__type __orig_type; + typedef typename __ptrtr_not_void<__orig_type>::__type __element_type; + + public: + static _Ptr pointer_to(__element_type& __e) + { return _Ptr::pointer_to(__e); } + }; + + /** + * @brief Uniform interface to all pointer-like types + * @ingroup pointer_abstractions + */ + template<typename _Ptr> + struct pointer_traits : __ptrtr_pointer_to<_Ptr> + { + /// The pointer type + typedef _Ptr pointer; + /// The type pointed to + typedef typename __ptrtr_elt_type<_Ptr>::__type element_type; + /// Type used to represent the difference between two pointers + typedef typename __ptrtr_diff_type<_Ptr>::__type difference_type; + + private: + /* TODO: replace __rebind<U> with alias template rebind<U> */ + /* + template<typename _Up> + using rebind<_Up> = typename __ptrtr_rebind<_Ptr, _Up>::__type; + */ + template<typename _Up> + struct __rebind + { typedef typename __ptrtr_rebind<_Ptr, _Up>::__type __type; }; + + // allocator_traits needs to use __rebind + template<typename> struct allocator_traits; + template<typename, typename> class __ptrtr_rebind_helper2; + }; + + /** + * @brief Partial specialization for built-in pointers. + * @ingroup pointer_abstractions + */ + template<typename _Tp> + struct pointer_traits<_Tp*> + { + /// The pointer type + typedef _Tp* pointer; + /// The type pointed to + typedef _Tp element_type; + /// Type used to represent the difference between two pointers + typedef ptrdiff_t difference_type; + + /* TODO: replace __rebind<U> with alias template rebind<U> */ + /* + template<typename _Up> + using rebind<_Up> = U*; + */ + template<typename U> + struct __rebind { typedef U* __type; }; + + /** + * @brief Obtain a pointer to an object + * @param r A reference to an object of type @c element_type + * @return @c addressof(r) + */ + static pointer + pointer_to(typename __ptrtr_not_void<element_type>::__type& __r) + { return std::addressof(__r); } + }; + +_GLIBCXX_END_NAMESPACE_VERSION +} // namespace std + +#endif + +#endif |