include/string_view

// -*- C++ -*-
//===------------------------ string_view ---------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_STRING_VIEW
#define _LIBCPP_STRING_VIEW

/*
string_view synopsis

namespace std {

 // 7.2, Class template basic_string_view
 template<class charT, class traits = char_traits<charT>>
 class basic_string_view;

 // 7.9, basic_string_view non-member comparison functions
 template<class charT, class traits>
 constexpr bool operator==(basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 template<class charT, class traits>
 constexpr bool operator!=(basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 template<class charT, class traits>
 constexpr bool operator< (basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 template<class charT, class traits>
 constexpr bool operator> (basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 template<class charT, class traits>
 constexpr bool operator<=(basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 template<class charT, class traits>
 constexpr bool operator>=(basic_string_view<charT, traits> x,
 basic_string_view<charT, traits> y) noexcept;
 // see below, sufficient additional overloads of comparison functions

 // 7.10, Inserters and extractors
 template<class charT, class traits>
 basic_ostream<charT, traits>&
 operator<<(basic_ostream<charT, traits>& os,
 basic_string_view<charT, traits> str);

 // basic_string_view typedef names
 typedef basic_string_view<char> string_view;
 typedef basic_string_view<char16_t> u16string_view;
 typedef basic_string_view<char32_t> u32string_view;
 typedef basic_string_view<wchar_t> wstring_view;

 template<class charT, class traits = char_traits<charT>>
 class basic_string_view {
 public:
 // types
 typedef traits traits_type;
 typedef charT value_type;
 typedef charT* pointer;
 typedef const charT* const_pointer;
 typedef charT& reference;
 typedef const charT& const_reference;
 typedef implementation-defined const_iterator;
 typedef const_iterator iterator;
 typedef reverse_iterator<const_iterator> const_reverse_iterator;
 typedef const_reverse_iterator reverse_iterator;
 typedef size_t size_type;
 typedef ptrdiff_t difference_type;
 static constexpr size_type npos = size_type(-1);

 // 7.3, basic_string_view constructors and assignment operators
 constexpr basic_string_view() noexcept;
 constexpr basic_string_view(const basic_string_view&) noexcept = default;
 basic_string_view& operator=(const basic_string_view&) noexcept = default;
 template<class Allocator>
 constexpr basic_string_view(const charT* str);
 constexpr basic_string_view(const charT* str, size_type len);

 // 7.4, basic_string_view iterator support
 constexpr const_iterator begin() const noexcept;
 constexpr const_iterator end() const noexcept;
 constexpr const_iterator cbegin() const noexcept;
 constexpr const_iterator cend() const noexcept;
 const_reverse_iterator rbegin() const noexcept;
 const_reverse_iterator rend() const noexcept;
 const_reverse_iterator crbegin() const noexcept;
 const_reverse_iterator crend() const noexcept;

 // 7.5, basic_string_view capacity
 constexpr size_type size() const noexcept;
 constexpr size_type length() const noexcept;
 constexpr size_type max_size() const noexcept;
 constexpr bool empty() const noexcept;

 // 7.6, basic_string_view element access
 constexpr const_reference operator[](size_type pos) const;
 constexpr const_reference at(size_type pos) const;
 constexpr const_reference front() const;
 constexpr const_reference back() const;
 constexpr const_pointer data() const noexcept;

 // 7.7, basic_string_view modifiers
 constexpr void clear() noexcept;
 constexpr void remove_prefix(size_type n);
 constexpr void remove_suffix(size_type n);
 constexpr void swap(basic_string_view& s) noexcept;

 size_type copy(charT* s, size_type n, size_type pos = 0) const;

 constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
 constexpr int compare(basic_string_view s) const noexcept;
 constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
 constexpr int compare(size_type pos1, size_type n1,
 basic_string_view s, size_type pos2, size_type n2) const;
 constexpr int compare(const charT* s) const;
 constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
 constexpr int compare(size_type pos1, size_type n1,
 const charT* s, size_type n2) const;
 constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
 constexpr size_type find(charT c, size_type pos = 0) const noexcept;
 constexpr size_type find(const charT* s, size_type pos, size_type n) const;
 constexpr size_type find(const charT* s, size_type pos = 0) const;
 constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
 constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
 constexpr size_type rfind(const charT* s, size_type pos, size_type n) const;
 constexpr size_type rfind(const charT* s, size_type pos = npos) const;
 constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
 constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
 constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const;
 constexpr size_type find_first_of(const charT* s, size_type pos = 0) const;
 constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
 constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
 constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const;
 constexpr size_type find_last_of(const charT* s, size_type pos = npos) const;
 constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
 constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
 constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const;
 constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const;
 constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
 constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
 constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const;
 constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const;

 private:
 const_pointer data_; // exposition only
 size_type size_; // exposition only
 };

 // 7.11, Hash support
 template <class T> struct hash;
 template <> struct hash<string_view>;
 template <> struct hash<u16string_view>;
 template <> struct hash<u32string_view>;
 template <> struct hash<wstring_view>;

} // namespace std


*/

#include <__config>

#include <__string>
#include <algorithm>
#include <iterator>
#include <__debug>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template<class _CharT, class _Traits = char_traits<_CharT> >
class _LIBCPP_TYPE_VIS_ONLY basic_string_view {
public:
// types
typedef _Traits traits_type;
typedef _CharT value_type;
typedef const _CharT* pointer;
typedef const _CharT* const_pointer;
typedef const _CharT& reference;
typedef const _CharT& const_reference;
typedef const_pointer const_iterator; // See [string.view.iterators]
typedef const_iterator iterator;
typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
typedef const_reverse_iterator reverse_iterator;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);

// [string.view.cons], construct/copy
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
basic_string_view(const basic_string_view&) _NOEXCEPT = default;

_LIBCPP_INLINE_VISIBILITY
basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
basic_string_view(const _CharT* __s, size_type __len)
: __data(__s), __size(__len)
{
// #if _LIBCPP_STD_VER > 11
// _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
// #endif
}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
basic_string_view(const _CharT* __s)
: __data(__s), __size(_Traits::length(__s)) {}

// [string.view.iterators], iterators
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_iterator begin() const _NOEXCEPT { return cbegin(); }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_iterator end() const _NOEXCEPT { return cend(); }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_iterator cbegin() const _NOEXCEPT { return __data; }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_iterator cend() const _NOEXCEPT { return __data + __size; }

_LIBCPP_INLINE_VISIBILITY
const_reverse_iterator rbegin() const _NOEXCEPT { return const_reverse_iterator(cend()); }

_LIBCPP_INLINE_VISIBILITY
const_reverse_iterator rend() const _NOEXCEPT { return const_reverse_iterator(cbegin()); }

_LIBCPP_INLINE_VISIBILITY
const_reverse_iterator crbegin() const _NOEXCEPT { return const_reverse_iterator(cend()); }

_LIBCPP_INLINE_VISIBILITY
const_reverse_iterator crend() const _NOEXCEPT { return const_reverse_iterator(cbegin()); }

// [string.view.capacity], capacity
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
size_type size() const _NOEXCEPT { return __size; }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
size_type length() const _NOEXCEPT { return __size; }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }

_LIBCPP_CONSTEXPR bool _LIBCPP_INLINE_VISIBILITY
empty() const _NOEXCEPT { return __size == 0; }

// [string.view.access], element access
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_reference operator[](size_type __pos) const _NOEXCEPT { return __data[__pos]; }

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_reference at(size_type __pos) const
{
return __pos >= size()
? (__libcpp_throw(out_of_range("string_view::at")), __data[0])
: __data[__pos];
}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_reference front() const
{
return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_reference back() const
{
return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
const_pointer data() const _NOEXCEPT { return __data; }

// [string.view.modifiers], modifiers:
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
void clear() _NOEXCEPT
{
__data = nullptr;
__size = 0;
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
void remove_prefix(size_type __n) _NOEXCEPT
{
_LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
__data += __n;
__size -= __n;
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
void remove_suffix(size_type __n) _NOEXCEPT
{
_LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
__size -= __n;
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
void swap(basic_string_view& __other) _NOEXCEPT
{
const value_type *__p = __data;
__data = __other.__data;
__other.__data = __p;

size_type __sz = __size;
__size = __other.__size;
__other.__size = __sz;
}

_LIBCPP_INLINE_VISIBILITY
size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
{
if (__pos > size())
__libcpp_throw(out_of_range("string_view::copy"));
size_type __rlen = _VSTD::min( __n, size() - __pos );
copy_n(begin() + __pos, __rlen, __s );
return __rlen;
}

_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
{
return __pos > size()
? (__libcpp_throw((out_of_range("string_view::substr"))), basic_string_view())
: basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
{
size_type __rlen = _VSTD::min( size(), __sv.size());
int __retval = _Traits::compare(data(), __sv.data(), __rlen);
if ( __retval == 0 ) // first __rlen chars matched
__retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
return __retval;
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
{
return substr(__pos1, __n1).compare(__sv);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
int compare( size_type __pos1, size_type __n1, 
basic_string_view _sv, size_type __pos2, size_type __n2) const
{
return substr(__pos1, __n1).compare(_sv.substr(__pos2, __n2));
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
int compare(const _CharT* __s) const _NOEXCEPT
{
return compare(basic_string_view(__s));
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
{
return substr(__pos1, __n1).compare(basic_string_view(__s));
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
{
return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
}

// find
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
return __str_find<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
{
return __str_find<value_type, size_type, traits_type, npos>
(data(), size(), __c, __pos);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
return __str_find<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find(const _CharT* __s, size_type __pos = 0) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
return __str_find<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

// rfind
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
return __str_rfind<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
{
return __str_rfind<value_type, size_type, traits_type, npos>
(data(), size(), __c, __pos);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
return __str_rfind<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type rfind(const _CharT* __s, size_type __pos=npos) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
return __str_rfind<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

// find_first_of
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
return __str_find_first_of<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
{ return find(__c, __pos); }

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
return __str_find_first_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_of(const _CharT* __s, size_type __pos=0) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
return __str_find_first_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

// find_last_of
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
return __str_find_last_of<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
{ return rfind(__c, __pos); }

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
return __str_find_last_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_of(const _CharT* __s, size_type __pos=npos) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
return __str_find_last_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

// find_first_not_of
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
return __str_find_first_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
{
return __str_find_first_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __c, __pos);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
return __str_find_first_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
return __str_find_first_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

// find_last_not_of
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
{
_LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
return __str_find_last_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s.data(), __pos, __s.size());
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
{
return __str_find_last_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __c, __pos);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
{
_LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
return __str_find_last_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, __n);
}

_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const
{
_LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
return __str_find_last_not_of<value_type, size_type, traits_type, npos>
(data(), size(), __s, __pos, traits_type::length(__s));
}

private:
const value_type* __data;
size_type __size;
};


// [string.view.comparison]
// operator ==
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator==(basic_string_view<_CharT, _Traits> __lhs,
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size()) return false;
return __lhs.compare(__rhs) == 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator==(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size()) return false;
return __lhs.compare(__rhs) == 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size()) return false;
return __lhs.compare(__rhs) == 0;
}


// operator !=
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size())
return true;
return __lhs.compare(__rhs) != 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size())
return true;
return __lhs.compare(__rhs) != 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
if ( __lhs.size() != __rhs.size())
return true;
return __lhs.compare(__rhs) != 0;
}


// operator <
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) < 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) < 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) < 0;
}


// operator >
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) > 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator>(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) > 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) > 0;
}


// operator <=
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) <= 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) <= 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) <= 0;
}


// operator >=
template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) >= 0;
}


template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) >= 0;
}

template<class _CharT, class _Traits>
_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
{
return __lhs.compare(__rhs) >= 0;
}

typedef basic_string_view<char> string_view;
typedef basic_string_view<char16_t> u16string_view;
typedef basic_string_view<char32_t> u32string_view;
typedef basic_string_view<wchar_t> wstring_view;

// [string.view.hash]
template<class _CharT, class _Traits>
struct _LIBCPP_TYPE_VIS_ONLY hash<basic_string_view<_CharT, _Traits> >
 : public unary_function<basic_string_view<_CharT, _Traits>, size_t>
{
 size_t operator()(const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT;
};

template<class _CharT, class _Traits>
size_t
hash<basic_string_view<_CharT, _Traits> >::operator()(
 const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT
{
 return __do_string_hash(__val.data(), __val.data() + __val.size());
}

#if _LIBCPP_STD_VER > 11

template <class _CharT, class _Traits>
__quoted_output_proxy<_CharT, const _CharT *, _Traits>
quoted (basic_string_view <_CharT, _Traits> __sv,
 _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
{
 return __quoted_output_proxy<_CharT, const _CharT *, _Traits> 
 ( __sv.data(), __sv.data() + __sv.size(), __delim, __escape );
}
#endif // _LIBCPP_STD_VER > 11

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_STRING_VIEW