llvm-project/libcxx/test/support/constexpr_char_traits.hpp

138 lines
4.1 KiB
C++

// -*- C++ -*-
//===-------_------------ constexpr_char_traits ---------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef _CONSTEXPR_CHAR_TRAITS
#define _CONSTEXPR_CHAR_TRAITS
#include <__config>
#include <string>
template <class _CharT>
struct constexpr_char_traits
{
typedef _CharT char_type;
typedef int int_type;
typedef std::streamoff off_type;
typedef std::streampos pos_type;
typedef std::mbstate_t state_type;
static _LIBCPP_CONSTEXPR_AFTER_CXX11 void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
{__c1 = __c2;}
static _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 < __c2;}
static _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(const char_type* __s1, const char_type* __s2, size_t __n);
static _LIBCPP_CONSTEXPR_AFTER_CXX11 size_t length(const char_type* __s);
static _LIBCPP_CONSTEXPR_AFTER_CXX11 const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
static _LIBCPP_CONSTEXPR_AFTER_CXX11 char_type* move(char_type* __s1, const char_type* __s2, size_t __n);
static _LIBCPP_CONSTEXPR_AFTER_CXX11 char_type* copy(char_type* __s1, const char_type* __s2, size_t __n);
static _LIBCPP_CONSTEXPR_AFTER_CXX11 char_type* assign(char_type* __s, size_t __n, char_type __a);
static _LIBCPP_CONSTEXPR int_type not_eof(int_type __c) _NOEXCEPT
{return eq_int_type(__c, eof()) ? ~eof() : __c;}
static _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
{return char_type(__c);}
static _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
{return int_type(__c);}
static _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
{return int_type(EOF);}
};
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 int
constexpr_char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
for (; __n; --__n, ++__s1, ++__s2)
{
if (lt(*__s1, *__s2))
return -1;
if (lt(*__s2, *__s1))
return 1;
}
return 0;
}
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 size_t
constexpr_char_traits<_CharT>::length(const char_type* __s)
{
size_t __len = 0;
for (; !eq(*__s, char_type(0)); ++__s)
++__len;
return __len;
}
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 const _CharT*
constexpr_char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
{
for (; __n; --__n)
{
if (eq(*__s, __a))
return __s;
++__s;
}
return 0;
}
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _CharT*
constexpr_char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n)
{
char_type* __r = __s1;
if (__s1 < __s2)
{
for (; __n; --__n, ++__s1, ++__s2)
assign(*__s1, *__s2);
}
else if (__s2 < __s1)
{
__s1 += __n;
__s2 += __n;
for (; __n; --__n)
assign(*--__s1, *--__s2);
}
return __r;
}
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _CharT*
constexpr_char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n)
{
_LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
char_type* __r = __s1;
for (; __n; --__n, ++__s1, ++__s2)
assign(*__s1, *__s2);
return __r;
}
template <class _CharT>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _CharT*
constexpr_char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a)
{
char_type* __r = __s;
for (; __n; --__n, ++__s)
assign(*__s, __a);
return __r;
}
#endif // _CONSTEXPR_CHAR_TRAITS