forked from KolibriOS/kolibrios
9d5ad505ec
git-svn-id: svn://kolibrios.org@5134 a494cfbc-eb01-0410-851d-a64ba20cac60
425 lines
9.6 KiB
C++
425 lines
9.6 KiB
C++
// The -*- C++ -*- type traits classes for internal use in libstdc++
|
|
|
|
// Copyright (C) 2000-2013 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
|
|
// 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/cpp_type_traits.h
|
|
* This is an internal header file, included by other library headers.
|
|
* Do not attempt to use it directly. @headername{ext/type_traits}
|
|
*/
|
|
|
|
// Written by Gabriel Dos Reis <dosreis@cmla.ens-cachan.fr>
|
|
|
|
#ifndef _CPP_TYPE_TRAITS_H
|
|
#define _CPP_TYPE_TRAITS_H 1
|
|
|
|
#pragma GCC system_header
|
|
|
|
#include <bits/c++config.h>
|
|
|
|
//
|
|
// This file provides some compile-time information about various types.
|
|
// These representations were designed, on purpose, to be constant-expressions
|
|
// and not types as found in <bits/type_traits.h>. In particular, they
|
|
// can be used in control structures and the optimizer hopefully will do
|
|
// the obvious thing.
|
|
//
|
|
// Why integral expressions, and not functions nor types?
|
|
// Firstly, these compile-time entities are used as template-arguments
|
|
// so function return values won't work: We need compile-time entities.
|
|
// We're left with types and constant integral expressions.
|
|
// Secondly, from the point of view of ease of use, type-based compile-time
|
|
// information is -not- *that* convenient. On has to write lots of
|
|
// overloaded functions and to hope that the compiler will select the right
|
|
// one. As a net effect, the overall structure isn't very clear at first
|
|
// glance.
|
|
// Thirdly, partial ordering and overload resolution (of function templates)
|
|
// is highly costly in terms of compiler-resource. It is a Good Thing to
|
|
// keep these resource consumption as least as possible.
|
|
//
|
|
// See valarray_array.h for a case use.
|
|
//
|
|
// -- Gaby (dosreis@cmla.ens-cachan.fr) 2000-03-06.
|
|
//
|
|
// Update 2005: types are also provided and <bits/type_traits.h> has been
|
|
// removed.
|
|
//
|
|
|
|
// Forward declaration hack, should really include this from somewhere.
|
|
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
|
|
{
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
template<typename _Iterator, typename _Container>
|
|
class __normal_iterator;
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
|
|
namespace std _GLIBCXX_VISIBILITY(default)
|
|
{
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
struct __true_type { };
|
|
struct __false_type { };
|
|
|
|
template<bool>
|
|
struct __truth_type
|
|
{ typedef __false_type __type; };
|
|
|
|
template<>
|
|
struct __truth_type<true>
|
|
{ typedef __true_type __type; };
|
|
|
|
// N.B. The conversions to bool are needed due to the issue
|
|
// explained in c++/19404.
|
|
template<class _Sp, class _Tp>
|
|
struct __traitor
|
|
{
|
|
enum { __value = bool(_Sp::__value) || bool(_Tp::__value) };
|
|
typedef typename __truth_type<__value>::__type __type;
|
|
};
|
|
|
|
// Compare for equality of types.
|
|
template<typename, typename>
|
|
struct __are_same
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
struct __are_same<_Tp, _Tp>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
// Holds if the template-argument is a void type.
|
|
template<typename _Tp>
|
|
struct __is_void
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_void<void>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// Integer types
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_integer
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
// Thirteen specializations (yes there are eleven standard integer
|
|
// types; <em>long long</em> and <em>unsigned long long</em> are
|
|
// supported as extensions)
|
|
template<>
|
|
struct __is_integer<bool>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<signed char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<unsigned char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
# ifdef _GLIBCXX_USE_WCHAR_T
|
|
template<>
|
|
struct __is_integer<wchar_t>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
# endif
|
|
|
|
#if __cplusplus >= 201103L
|
|
template<>
|
|
struct __is_integer<char16_t>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<char32_t>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
#endif
|
|
|
|
template<>
|
|
struct __is_integer<short>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<unsigned short>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<int>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<unsigned int>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<long>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<unsigned long>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<long long>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_integer<unsigned long long>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// Floating point types
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_floating
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
// three specializations (float, double and 'long double')
|
|
template<>
|
|
struct __is_floating<float>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_floating<double>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_floating<long double>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// Pointer types
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_pointer
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<typename _Tp>
|
|
struct __is_pointer<_Tp*>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// Normal iterator type
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_normal_iterator
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<typename _Iterator, typename _Container>
|
|
struct __is_normal_iterator< __gnu_cxx::__normal_iterator<_Iterator,
|
|
_Container> >
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// An arithmetic type is an integer type or a floating point type
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_arithmetic
|
|
: public __traitor<__is_integer<_Tp>, __is_floating<_Tp> >
|
|
{ };
|
|
|
|
//
|
|
// A fundamental type is `void' or and arithmetic type
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_fundamental
|
|
: public __traitor<__is_void<_Tp>, __is_arithmetic<_Tp> >
|
|
{ };
|
|
|
|
//
|
|
// A scalar type is an arithmetic type or a pointer type
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_scalar
|
|
: public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >
|
|
{ };
|
|
|
|
//
|
|
// For use in std::copy and std::find overloads for streambuf iterators.
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_char
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_char<char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
#ifdef _GLIBCXX_USE_WCHAR_T
|
|
template<>
|
|
struct __is_char<wchar_t>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
#endif
|
|
|
|
template<typename _Tp>
|
|
struct __is_byte
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_byte<char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_byte<signed char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
template<>
|
|
struct __is_byte<unsigned char>
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
|
|
//
|
|
// Move iterator type
|
|
//
|
|
template<typename _Tp>
|
|
struct __is_move_iterator
|
|
{
|
|
enum { __value = 0 };
|
|
typedef __false_type __type;
|
|
};
|
|
|
|
#if __cplusplus >= 201103L
|
|
template<typename _Iterator>
|
|
class move_iterator;
|
|
|
|
template<typename _Iterator>
|
|
struct __is_move_iterator< move_iterator<_Iterator> >
|
|
{
|
|
enum { __value = 1 };
|
|
typedef __true_type __type;
|
|
};
|
|
#endif
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
|
|
#endif //_CPP_TYPE_TRAITS_H
|