LCOM1920-T02G10

// -*- 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_LFTS_STRING_VIEW

#define _LIBCPP_LFTS_STRING_VIEW

/*

string_view synopsis

namespace std {

 namespace experimental {

  inline namespace library_fundamentals_v1 {

    // 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>

      basic_string_view(const basic_string<charT, traits, Allocator>& str) noexcept;

      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;

      // 7.8, basic_string_view string operations

      template<class Allocator>

      explicit operator basic_string<charT, traits, Allocator>() const;

      template<class Allocator = allocator<charT>>

      basic_string<charT, traits, Allocator> to_string(

        const Allocator& a = Allocator()) const;

      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

    };

  }  // namespace fundamentals_v1

 }  // namespace experimental

  // 7.11, Hash support

  template <class T> struct hash;

  template <> struct hash<experimental::string_view>;

  template <> struct hash<experimental::u16string_view>;

  template <> struct hash<experimental::u32string_view>;

  template <> struct hash<experimental::wstring_view>;

}  // namespace std

*/

#include <experimental/__config>

#include <string>

#include <algorithm>

#include <iterator>

#include <ostream>

#include <iomanip>

#include <__debug>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

#pragma GCC system_header

#endif

_LIBCPP_BEGIN_NAMESPACE_LFTS

    template<class _CharT, class _Traits = _VSTD::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;

        template<class _Allocator>

        _LIBCPP_INLINE_VISIBILITY

        basic_string_view(const basic_string<_CharT, _Traits, _Allocator>& __str) _NOEXCEPT

            : __data (__str.data()), __size(__str.size()) {}

        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY

        basic_string_view(const _CharT* __s, size_type __len)

            : __data(__s), __size(__len)

        {

//             _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): recieved nullptr");

        }

        _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 _VSTD::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 { return __data[__pos]; }

        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY

        const_reference at(size_type __pos) const

        {

            return __pos >= size()

                ? (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;

//             _VSTD::swap( __data, __other.__data );

//             _VSTD::swap( __size, __other.__size );

        }

        // [string.view.ops], string operations:

        template<class _Allocator>

        _LIBCPP_INLINE_VISIBILITY

        _LIBCPP_EXPLICIT operator basic_string<_CharT, _Traits, _Allocator>() const

        { return basic_string<_CharT, _Traits, _Allocator>( begin(), end()); }

        template<class _Allocator = allocator<_CharT> >

        _LIBCPP_INLINE_VISIBILITY

        basic_string<_CharT, _Traits, _Allocator>

        to_string( const _Allocator& __a = _Allocator()) const

        { return basic_string<_CharT, _Traits, _Allocator> ( begin(), end(), __a ); }

        size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const

        {

            if ( __pos > size())

                throw out_of_range("string_view::copy");

            size_type __rlen = _VSTD::min( __n, size() - __pos );

            _VSTD::copy_n(begin() + __pos, __rlen, __s );

            return __rlen;

        }

        _LIBCPP_CONSTEXPR

        basic_string_view substr(size_type __pos = 0, size_type __n = npos) const

        {

//             if (__pos > size())

//                 throw out_of_range("string_view::substr");

//             size_type __rlen = _VSTD::min( __n, size() - __pos );

//             return basic_string_view(data() + __pos, __rlen);

            return __pos > size()

                ? throw out_of_range("string_view::substr")

                : 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

        {

            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(): recieved nullptr");

            return _VSTD::__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 _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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 _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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 _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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 _VSTD::__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(): recieved nullptr");

            return _VSTD::__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(): recieved nullptr");

            return _VSTD::__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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::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 _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs,

                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT

    {

        return __lhs.compare(__rhs) >= 0;

    }

    // [string.view.io]

    template<class _CharT, class _Traits>

    basic_ostream<_CharT, _Traits>&

    operator<<(basic_ostream<_CharT, _Traits>& __os, basic_string_view<_CharT, _Traits> __sv)

    {

        return _VSTD::__put_character_sequence(__os, __sv.data(), __sv.size());

    }

  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;

_LIBCPP_END_NAMESPACE_LFTS

_LIBCPP_BEGIN_NAMESPACE_STD

// [string.view.hash]

// Shamelessly stolen from <string>

template<class _CharT, class _Traits>

struct _LIBCPP_TYPE_VIS_ONLY hash<std::experimental::basic_string_view<_CharT, _Traits> >

    : public unary_function<std::experimental::basic_string_view<_CharT, _Traits>, size_t>

{

    size_t operator()(const std::experimental::basic_string_view<_CharT, _Traits>& __val) const _NOEXCEPT;

};

template<class _CharT, class _Traits>

size_t

hash<std::experimental::basic_string_view<_CharT, _Traits> >::operator()(

        const std::experimental::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 ( std::experimental::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_END_NAMESPACE_STD

#endif // _LIBCPP_LFTS_STRING_VIEW