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// Components for manipulating non-owning sequences of characters -*- C++ -*-
// Copyright (C) 2013-2014 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 experimental/string_view
* This is a Standard C++ Library header.
*/
//
// N3762 basic_string_view library
//
#ifndef _GLIBCXX_EXPERIMENTAL_STRING_VIEW
#define _GLIBCXX_EXPERIMENTAL_STRING_VIEW 1
#pragma GCC system_header
#if __cplusplus <= 201103L
# include <bits/c++14_warning.h>
#else
#include <debug/debug.h>
#include <string>
#include <limits>
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace experimental
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @class basic_string_view <string_view>
* @brief A non-owning reference to a string.
*
* @ingroup strings
* @ingroup sequences
*
* @tparam _CharT Type of character
* @tparam _Traits Traits for character type, defaults to
* char_traits<_CharT>.
*
* A basic_string_view looks like this:
*
* @code
* _CharT* _M_str
* size_t _M_len
* @endcode
*
* A basic_string_view represents an empty string with a static constexpr
* length one string:
*
* @code
* static constexpr value_type _S_empty_str[1]{0};
* @endcode
*/
template<typename _CharT, typename _Traits = char_traits<_CharT>>
class basic_string_view
{
public:
// types
using traits_type = _Traits;
using value_type = _CharT;
using pointer = const _CharT*;
using const_pointer = const _CharT*;
using reference = const _CharT&;
using const_reference = const _CharT&;
using const_iterator = const _CharT*;
using iterator = const_iterator;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
using reverse_iterator = const_reverse_iterator;
using size_type = size_t;
using difference_type = ptrdiff_t;
static constexpr size_type npos = size_type(-1);
// [string.view.cons], construct/copy
constexpr
basic_string_view() noexcept
: _M_len{0}, _M_str{_S_empty_str}
{ }
constexpr basic_string_view(const basic_string_view&) noexcept = default;
template<typename _Allocator>
basic_string_view(const basic_string<_CharT, _Traits,
_Allocator>& __str) noexcept
: _M_len{__str.length()}, _M_str{__str.data()}
{ }
constexpr basic_string_view(const _CharT* __str)
: _M_len{__str == nullptr ? 0 : traits_type::length(__str)},
_M_str{__str == nullptr ? _S_empty_str : __str}
{ }
constexpr basic_string_view(const _CharT* __str, size_type __len)
: _M_len{__str == nullptr ? 0 :__len},
_M_str{__str == nullptr ? _S_empty_str : __str}
{ }
basic_string_view&
operator=(const basic_string_view&) noexcept = default;
// [string.view.iterators], iterators
constexpr const_iterator
begin() const noexcept
{ return this->_M_str; }
constexpr const_iterator
end() const noexcept
{ return this->_M_str + this->_M_len; }
constexpr const_iterator
cbegin() const noexcept
{ return this->_M_str; }
constexpr const_iterator
cend() const noexcept
{ return this->_M_str + this->_M_len; }
const_reverse_iterator
rbegin() const noexcept
{ return std::reverse_iterator<const_iterator>(this->end()); }
const_reverse_iterator
rend() const noexcept
{ return std::reverse_iterator<const_iterator>(this->begin()); }
const_reverse_iterator
crbegin() const noexcept
{ return std::reverse_iterator<const_iterator>(this->end()); }
const_reverse_iterator
crend() const noexcept
{ return std::reverse_iterator<const_iterator>(this->begin()); }
// [string.view.capacity], capacity
constexpr size_type
size() const noexcept
{ return this->_M_len; }
constexpr size_type
length() const noexcept
{ return _M_len; }
constexpr size_type
max_size() const noexcept
{ return ((npos - sizeof(size_type) - sizeof(void*))
/ sizeof(value_type) / 4); }
constexpr bool
empty() const noexcept
{ return this->_M_len == 0; }
// [string.view.access], element access
constexpr const _CharT&
operator[](size_type __pos) const
{
// TODO: Assert to restore in a way compatible with the constexpr.
// _GLIBCXX_DEBUG_ASSERT(__pos < this->_M_len);
return *(this->_M_str + __pos);
}
constexpr const _CharT&
at(size_type __pos) const
{
return __pos < this->_M_len
? *(this->_M_str + __pos)
: (__throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
"(which is %zu) >= this->size() "
"(which is %zu)"),
__pos, this->size()),
_S_empty_str[0]);
}
constexpr const _CharT&
front() const
{
// TODO: Assert to restore in a way compatible with the constexpr.
// _GLIBCXX_DEBUG_ASSERT(this->_M_len > 0);
return *this->_M_str;
}
constexpr const _CharT&
back() const
{
// TODO: Assert to restore in a way compatible with the constexpr.
// _GLIBCXX_DEBUG_ASSERT(this->_M_len > 0);
return *(this->_M_str + this->_M_len - 1);
}
constexpr const _CharT*
data() const noexcept
{ return this->_M_str; }
// [string.view.modifiers], modifiers:
void
clear() noexcept
{
this->_M_len = 0;
this->_M_str = _S_empty_str;
}
void
remove_prefix(size_type __n)
{
_GLIBCXX_DEBUG_ASSERT(this->_M_len >= __n);
this->_M_str += __n;
this->_M_len -= __n;
}
void
remove_suffix(size_type __n)
{ this->_M_len -= __n; }
void
swap(basic_string_view& __sv) noexcept
{
std::swap(this->_M_len, __sv._M_len);
std::swap(this->_M_str, __sv._M_str);
}
// [string.view.ops], string operations:
template<typename _Allocator>
explicit operator basic_string<_CharT, _Traits, _Allocator>() const
{
return basic_string<_CharT, _Traits, _Allocator>
(this->_M_len, this->_M_str);
}
size_type
copy(_CharT* __str, size_type __n, size_type __pos = 0) const
{
__glibcxx_requires_string_len(__str, __n);
if (__pos > this->_M_len)
__throw_out_of_range_fmt(__N("basic_string_view::copy: __pos "
"(which is %zu) > this->size() "
"(which is %zu)"),
__pos, this->size());
size_type __rlen{std::min(__n, size_type{this->_M_len - __pos})};
for (auto __begin = this->_M_str + __pos,
__end = __begin + __rlen; __begin != __end;)
*__str++ = *__begin++;
return __rlen;
}
// [string.view.ops], string operations:
constexpr basic_string_view
substr(size_type __pos, size_type __n=npos) const
{
return __pos <= this->_M_len
? basic_string_view{this->_M_str + __pos,
std::min(__n, size_type{this->_M_len - __pos})}
: (__throw_out_of_range_fmt(__N("basic_string_view::substr: __pos "
"(which is %zu) > this->size() "
"(which is %zu)"),
__pos, this->size()), basic_string_view{});
}
int
compare(basic_string_view __str) const noexcept
{
int __ret = traits_type::compare(this->_M_str, __str._M_str,
std::min(this->_M_len, __str._M_len));
if (__ret == 0)
__ret = _S_compare(this->_M_len, __str._M_len);
return __ret;
}
int
compare(size_type __pos1, size_type __n1, basic_string_view __str) const
{ return this->substr(__pos1, __n1).compare(__str); }
int
compare(size_type __pos1, size_type __n1,
basic_string_view __str, size_type __pos2, size_type __n2) const
{ return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2)); }
int
compare(const _CharT* __str) const noexcept
{ return this->compare(basic_string_view{__str}); }
int
compare(size_type __pos1, size_type __n1, const _CharT* __str) const
{ return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
int
compare(size_type __pos1, size_type __n1,
const _CharT* __str, size_type __n2) const
{
return this->substr(__pos1, __n1)
.compare(basic_string_view(__str, __n2));
}
size_type
find(basic_string_view __str, size_type __pos = 0) const noexcept
{ return this->find(__str._M_str, __pos, __str._M_len); }
size_type
find(_CharT __c, size_type __pos=0) const noexcept;
size_type
find(const _CharT* __str, size_type __pos, size_type __n) const;
size_type
find(const _CharT* __str, size_type __pos=0) const noexcept
{ return this->find(__str, __pos, traits_type::length(__str)); }
size_type
rfind(basic_string_view __str, size_type __pos = npos) const noexcept
{ return this->rfind(__str._M_str, __pos, __str._M_len); }
size_type
rfind(_CharT __c, size_type __pos = npos) const noexcept;
size_type
rfind(const _CharT* __str, size_type __pos, size_type __n) const;
size_type
rfind(const _CharT* __str, size_type __pos = npos) const noexcept
{ return this->rfind(__str, __pos, traits_type::length(__str)); }
size_type
find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
{ return this->find_first_of(__str._M_str, __pos, __str._M_len); }
size_type
find_first_of(_CharT __c, size_type __pos = 0) const noexcept
{ return this->find(__c, __pos); }
size_type
find_first_of(const _CharT* __str, size_type __pos, size_type __n) const;
size_type
find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
{ return this->find_first_of(__str, __pos, traits_type::length(__str)); }
size_type
find_last_of(basic_string_view __str,
size_type __pos = npos) const noexcept
{ return this->find_last_of(__str._M_str, __pos, __str._M_len); }
size_type
find_last_of(_CharT __c, size_type __pos=npos) const noexcept
{ return this->rfind(__c, __pos); }
size_type
find_last_of(const _CharT* __str, size_type __pos, size_type __n) const;
size_type
find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
{ return this->find_last_of(__str, __pos, traits_type::length(__str)); }
size_type
find_first_not_of(basic_string_view __str,
size_type __pos = 0) const noexcept
{ return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
size_type
find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
size_type
find_first_not_of(const _CharT* __str,
size_type __pos, size_type __n) const;
size_type
find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
{
return this->find_first_not_of(__str, __pos,
traits_type::length(__str));
}
size_type
find_last_not_of(basic_string_view __str,
size_type __pos = npos) const noexcept
{ return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
size_type
find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
size_type
find_last_not_of(const _CharT* __str,
size_type __pos, size_type __n) const;
size_type
find_last_not_of(const _CharT* __str,
size_type __pos = npos) const noexcept
{
return this->find_last_not_of(__str, __pos,
traits_type::length(__str));
}
private:
static constexpr const int
_S_compare(size_type __n1, size_type __n2) noexcept
{
return difference_type{__n1 - __n2} > std::numeric_limits<int>::max()
? std::numeric_limits<int>::max()
: difference_type{__n1 - __n2} < std::numeric_limits<int>::min()
? std::numeric_limits<int>::min()
: static_cast<int>(difference_type{__n1 - __n2});
}
static constexpr value_type _S_empty_str[1]{};
size_t _M_len;
const _CharT* _M_str;
};
// [string.view.comparison], non-member basic_string_view comparison functions
namespace __detail
{
// Identity transform to make ADL work with just one argument.
// See n3766.html.
template<typename _Tp = void>
struct __identity
{ typedef _Tp type; };
template<>
struct __identity<void>;
template<typename _Tp>
using __idt = typename __identity<_Tp>::type;
}
template<typename _CharT, typename _Traits>
bool
operator==(basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) == 0; }
template<typename _CharT, typename _Traits>
bool
operator==(basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return __x.compare(__y) == 0; }
template<typename _CharT, typename _Traits>
bool
operator==(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) == 0; }
template<typename _CharT, typename _Traits>
bool
operator!=(basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return !(__x == __y); }
template<typename _CharT, typename _Traits>
bool
operator!=(basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return !(__x == __y); }
template<typename _CharT, typename _Traits>
bool
operator!=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return !(__x == __y); }
template<typename _CharT, typename _Traits>
bool
operator< (basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) < 0; }
template<typename _CharT, typename _Traits>
bool
operator< (basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return __x.compare(__y) < 0; }
template<typename _CharT, typename _Traits>
bool
operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) < 0; }
template<typename _CharT, typename _Traits>
bool
operator> (basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) > 0; }
template<typename _CharT, typename _Traits>
bool
operator> (basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return __x.compare(__y) > 0; }
template<typename _CharT, typename _Traits>
bool
operator> (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) > 0; }
template<typename _CharT, typename _Traits>
bool
operator<=(basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) <= 0; }
template<typename _CharT, typename _Traits>
bool
operator<=(basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return __x.compare(__y) <= 0; }
template<typename _CharT, typename _Traits>
bool
operator<=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) <= 0; }
template<typename _CharT, typename _Traits>
bool
operator>=(basic_string_view<_CharT, _Traits> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) >= 0; }
template<typename _CharT, typename _Traits>
bool
operator>=(basic_string_view<_CharT, _Traits> __x,
__detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
{ return __x.compare(__y) >= 0; }
template<typename _CharT, typename _Traits>
bool
operator>=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
basic_string_view<_CharT, _Traits> __y) noexcept
{ return __x.compare(__y) >= 0; }
// [string.view.comparison], sufficient additional overloads of comparison functions
// [string.view.nonmem], other non-member basic_string_view functions
template<typename _CharT, typename _Traits = char_traits<_CharT>,
typename _Allocator = allocator<_CharT>>
basic_string<_CharT, _Traits, _Allocator>
to_string(basic_string_view<_CharT, _Traits> __str,
const _Allocator& __alloc = _Allocator())
{
return basic_string<_CharT, _Traits, _Allocator>
(__str.begin(), __str.end(), __alloc);
}
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
basic_string_view<_CharT,_Traits> __str)
{ return __ostream_insert(__os, __str.data(), __str.size()); }
// basic_string_view typedef names
using string_view = basic_string_view<char>;
#ifdef _GLIBCXX_USE_WCHAR_T
using wstring_view = basic_string_view<wchar_t>;
#endif
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
using u16string_view = basic_string_view<char16_t>;
using u32string_view = basic_string_view<char32_t>;
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace experimental
// [string.view.hash], hash support:
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
struct hash;
template<>
struct hash<experimental::string_view>
: public __hash_base<size_t, experimental::string_view>
{
size_t
operator()(const experimental::string_view& __str) const noexcept
{ return std::_Hash_impl::hash(__str.data(), __str.length()); }
};
template<>
struct __is_fast_hash<hash<experimental::string_view>> : std::false_type
{ };
#ifdef _GLIBCXX_USE_WCHAR_T
template<>
struct hash<experimental::wstring_view>
: public __hash_base<size_t, wstring>
{
size_t
operator()(const experimental::wstring_view& __s) const noexcept
{ return std::_Hash_impl::hash(__s.data(),
__s.length() * sizeof(wchar_t)); }
};
template<>
struct __is_fast_hash<hash<experimental::wstring_view>> : std::false_type
{ };
#endif
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
template<>
struct hash<experimental::u16string_view>
: public __hash_base<size_t, experimental::u16string_view>
{
size_t
operator()(const experimental::u16string_view& __s) const noexcept
{ return std::_Hash_impl::hash(__s.data(),
__s.length() * sizeof(char16_t)); }
};
template<>
struct __is_fast_hash<hash<experimental::u16string_view>> : std::false_type
{ };
template<>
struct hash<experimental::u32string_view>
: public __hash_base<size_t, experimental::u32string_view>
{
size_t
operator()(const experimental::u32string_view& __s) const noexcept
{ return std::_Hash_impl::hash(__s.data(),
__s.length() * sizeof(char32_t)); }
};
template<>
struct __is_fast_hash<hash<experimental::u32string_view>> : std::false_type
{ };
#endif
_GLIBCXX_END_NAMESPACE_VERSION
namespace experimental
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// I added these EMSR.
inline namespace literals
{
inline namespace string_view_literals
{
inline basic_string_view<char>
operator""sv(const char* __str, size_t __len)
{ return basic_string_view<char>{__str, __len}; }
#ifdef _GLIBCXX_USE_WCHAR_T
inline basic_string_view<wchar_t>
operator""sv(const wchar_t* __str, size_t __len)
{ return basic_string_view<wchar_t>{__str, __len}; }
#endif
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
inline basic_string_view<char16_t>
operator""sv(const char16_t* __str, size_t __len)
{ return basic_string_view<char16_t>{__str, __len}; }
inline basic_string_view<char32_t>
operator""sv(const char32_t* __str, size_t __len)
{ return basic_string_view<char32_t>{__str, __len}; }
#endif
}
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace experimental
} // namespace std
#include <experimental/string_view.tcc>
#endif // __cplusplus <= 201103L
#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW