--- /dev/null
+// Vendored from git changeset v1.4.0
+
+// Copyright 2017-2020 by Martin Moene
+//
+// string-view lite, a C++17-like string_view for C++98 and later.
+// For more information see https://github.com/martinmoene/string-view-lite
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#pragma once
+
+#ifndef NONSTD_SV_LITE_H_INCLUDED
+#define NONSTD_SV_LITE_H_INCLUDED
+
+#define string_view_lite_MAJOR 1
+#define string_view_lite_MINOR 4
+#define string_view_lite_PATCH 0
+
+#define string_view_lite_VERSION nssv_STRINGIFY(string_view_lite_MAJOR) "." nssv_STRINGIFY(string_view_lite_MINOR) "." nssv_STRINGIFY(string_view_lite_PATCH)
+
+#define nssv_STRINGIFY( x ) nssv_STRINGIFY_( x )
+#define nssv_STRINGIFY_( x ) #x
+
+// string-view lite configuration:
+
+#define nssv_STRING_VIEW_DEFAULT 0
+#define nssv_STRING_VIEW_NONSTD 1
+#define nssv_STRING_VIEW_STD 2
+
+#if !defined( nssv_CONFIG_SELECT_STRING_VIEW )
+# define nssv_CONFIG_SELECT_STRING_VIEW ( nssv_HAVE_STD_STRING_VIEW ? nssv_STRING_VIEW_STD : nssv_STRING_VIEW_NONSTD )
+#endif
+
+#if defined( nssv_CONFIG_SELECT_STD_STRING_VIEW ) || defined( nssv_CONFIG_SELECT_NONSTD_STRING_VIEW )
+# error nssv_CONFIG_SELECT_STD_STRING_VIEW and nssv_CONFIG_SELECT_NONSTD_STRING_VIEW are deprecated and removed, please use nssv_CONFIG_SELECT_STRING_VIEW=nssv_STRING_VIEW_...
+#endif
+
+#ifndef nssv_CONFIG_STD_SV_OPERATOR
+# define nssv_CONFIG_STD_SV_OPERATOR 0
+#endif
+
+#ifndef nssv_CONFIG_USR_SV_OPERATOR
+# define nssv_CONFIG_USR_SV_OPERATOR 1
+#endif
+
+#ifdef nssv_CONFIG_CONVERSION_STD_STRING
+# define nssv_CONFIG_CONVERSION_STD_STRING_CLASS_METHODS nssv_CONFIG_CONVERSION_STD_STRING
+# define nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS nssv_CONFIG_CONVERSION_STD_STRING
+#endif
+
+#ifndef nssv_CONFIG_CONVERSION_STD_STRING_CLASS_METHODS
+# define nssv_CONFIG_CONVERSION_STD_STRING_CLASS_METHODS 1
+#endif
+
+#ifndef nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+# define nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS 1
+#endif
+
+// Control presence of exception handling (try and auto discover):
+
+#ifndef nssv_CONFIG_NO_EXCEPTIONS
+# if defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)
+# define nssv_CONFIG_NO_EXCEPTIONS 0
+# else
+# define nssv_CONFIG_NO_EXCEPTIONS 1
+# endif
+#endif
+
+// C++ language version detection (C++20 is speculative):
+// Note: VC14.0/1900 (VS2015) lacks too much from C++14.
+
+#ifndef nssv_CPLUSPLUS
+# if defined(_MSVC_LANG ) && !defined(__clang__)
+# define nssv_CPLUSPLUS (_MSC_VER == 1900 ? 201103L : _MSVC_LANG )
+# else
+# define nssv_CPLUSPLUS __cplusplus
+# endif
+#endif
+
+#define nssv_CPP98_OR_GREATER ( nssv_CPLUSPLUS >= 199711L )
+#define nssv_CPP11_OR_GREATER ( nssv_CPLUSPLUS >= 201103L )
+#define nssv_CPP11_OR_GREATER_ ( nssv_CPLUSPLUS >= 201103L )
+#define nssv_CPP14_OR_GREATER ( nssv_CPLUSPLUS >= 201402L )
+#define nssv_CPP17_OR_GREATER ( nssv_CPLUSPLUS >= 201703L )
+#define nssv_CPP20_OR_GREATER ( nssv_CPLUSPLUS >= 202000L )
+
+// use C++17 std::string_view if available and requested:
+
+#if nssv_CPP17_OR_GREATER && defined(__has_include )
+# if __has_include( <string_view> )
+# define nssv_HAVE_STD_STRING_VIEW 1
+# else
+# define nssv_HAVE_STD_STRING_VIEW 0
+# endif
+#else
+# define nssv_HAVE_STD_STRING_VIEW 0
+#endif
+
+#define nssv_USES_STD_STRING_VIEW ( (nssv_CONFIG_SELECT_STRING_VIEW == nssv_STRING_VIEW_STD) || ((nssv_CONFIG_SELECT_STRING_VIEW == nssv_STRING_VIEW_DEFAULT) && nssv_HAVE_STD_STRING_VIEW) )
+
+#define nssv_HAVE_STARTS_WITH ( nssv_CPP20_OR_GREATER || !nssv_USES_STD_STRING_VIEW )
+#define nssv_HAVE_ENDS_WITH nssv_HAVE_STARTS_WITH
+
+//
+// Use C++17 std::string_view:
+//
+
+#if nssv_USES_STD_STRING_VIEW
+
+#include <string_view>
+
+// Extensions for std::string:
+
+#if nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+
+namespace nonstd {
+
+template< class CharT, class Traits, class Allocator = std::allocator<CharT> >
+std::basic_string<CharT, Traits, Allocator>
+to_string( std::basic_string_view<CharT, Traits> v, Allocator const & a = Allocator() )
+{
+ return std::basic_string<CharT,Traits, Allocator>( v.begin(), v.end(), a );
+}
+
+template< class CharT, class Traits, class Allocator >
+std::basic_string_view<CharT, Traits>
+to_string_view( std::basic_string<CharT, Traits, Allocator> const & s )
+{
+ return std::basic_string_view<CharT, Traits>( s.data(), s.size() );
+}
+
+// Literal operators sv and _sv:
+
+#if nssv_CONFIG_STD_SV_OPERATOR
+
+using namespace std::literals::string_view_literals;
+
+#endif
+
+#if nssv_CONFIG_USR_SV_OPERATOR
+
+inline namespace literals {
+inline namespace string_view_literals {
+
+
+constexpr std::string_view operator "" _sv( const char* str, size_t len ) noexcept // (1)
+{
+ return std::string_view{ str, len };
+}
+
+constexpr std::u16string_view operator "" _sv( const char16_t* str, size_t len ) noexcept // (2)
+{
+ return std::u16string_view{ str, len };
+}
+
+constexpr std::u32string_view operator "" _sv( const char32_t* str, size_t len ) noexcept // (3)
+{
+ return std::u32string_view{ str, len };
+}
+
+constexpr std::wstring_view operator "" _sv( const wchar_t* str, size_t len ) noexcept // (4)
+{
+ return std::wstring_view{ str, len };
+}
+
+}} // namespace literals::string_view_literals
+
+#endif // nssv_CONFIG_USR_SV_OPERATOR
+
+} // namespace nonstd
+
+#endif // nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+
+namespace nonstd {
+
+using std::string_view;
+using std::wstring_view;
+using std::u16string_view;
+using std::u32string_view;
+using std::basic_string_view;
+
+// literal "sv" and "_sv", see above
+
+using std::operator==;
+using std::operator!=;
+using std::operator<;
+using std::operator<=;
+using std::operator>;
+using std::operator>=;
+
+using std::operator<<;
+
+} // namespace nonstd
+
+#else // nssv_HAVE_STD_STRING_VIEW
+
+//
+// Before C++17: use string_view lite:
+//
+
+// Compiler versions:
+//
+// MSVC++ 6.0 _MSC_VER == 1200 nssv_COMPILER_MSVC_VERSION == 60 (Visual Studio 6.0)
+// MSVC++ 7.0 _MSC_VER == 1300 nssv_COMPILER_MSVC_VERSION == 70 (Visual Studio .NET 2002)
+// MSVC++ 7.1 _MSC_VER == 1310 nssv_COMPILER_MSVC_VERSION == 71 (Visual Studio .NET 2003)
+// MSVC++ 8.0 _MSC_VER == 1400 nssv_COMPILER_MSVC_VERSION == 80 (Visual Studio 2005)
+// MSVC++ 9.0 _MSC_VER == 1500 nssv_COMPILER_MSVC_VERSION == 90 (Visual Studio 2008)
+// MSVC++ 10.0 _MSC_VER == 1600 nssv_COMPILER_MSVC_VERSION == 100 (Visual Studio 2010)
+// MSVC++ 11.0 _MSC_VER == 1700 nssv_COMPILER_MSVC_VERSION == 110 (Visual Studio 2012)
+// MSVC++ 12.0 _MSC_VER == 1800 nssv_COMPILER_MSVC_VERSION == 120 (Visual Studio 2013)
+// MSVC++ 14.0 _MSC_VER == 1900 nssv_COMPILER_MSVC_VERSION == 140 (Visual Studio 2015)
+// MSVC++ 14.1 _MSC_VER >= 1910 nssv_COMPILER_MSVC_VERSION == 141 (Visual Studio 2017)
+// MSVC++ 14.2 _MSC_VER >= 1920 nssv_COMPILER_MSVC_VERSION == 142 (Visual Studio 2019)
+
+#if defined(_MSC_VER ) && !defined(__clang__)
+# define nssv_COMPILER_MSVC_VER (_MSC_VER )
+# define nssv_COMPILER_MSVC_VERSION (_MSC_VER / 10 - 10 * ( 5 + (_MSC_VER < 1900 ) ) )
+#else
+# define nssv_COMPILER_MSVC_VER 0
+# define nssv_COMPILER_MSVC_VERSION 0
+#endif
+
+#define nssv_COMPILER_VERSION( major, minor, patch ) ( 10 * ( 10 * (major) + (minor) ) + (patch) )
+
+#if defined(__clang__)
+# define nssv_COMPILER_CLANG_VERSION nssv_COMPILER_VERSION(__clang_major__, __clang_minor__, __clang_patchlevel__)
+#else
+# define nssv_COMPILER_CLANG_VERSION 0
+#endif
+
+#if defined(__GNUC__) && !defined(__clang__)
+# define nssv_COMPILER_GNUC_VERSION nssv_COMPILER_VERSION(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__)
+#else
+# define nssv_COMPILER_GNUC_VERSION 0
+#endif
+
+// half-open range [lo..hi):
+#define nssv_BETWEEN( v, lo, hi ) ( (lo) <= (v) && (v) < (hi) )
+
+// Presence of language and library features:
+
+#ifdef _HAS_CPP0X
+# define nssv_HAS_CPP0X _HAS_CPP0X
+#else
+# define nssv_HAS_CPP0X 0
+#endif
+
+// Unless defined otherwise below, consider VC14 as C++11 for variant-lite:
+
+#if nssv_COMPILER_MSVC_VER >= 1900
+# undef nssv_CPP11_OR_GREATER
+# define nssv_CPP11_OR_GREATER 1
+#endif
+
+#define nssv_CPP11_90 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1500)
+#define nssv_CPP11_100 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1600)
+#define nssv_CPP11_110 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1700)
+#define nssv_CPP11_120 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1800)
+#define nssv_CPP11_140 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1900)
+#define nssv_CPP11_141 (nssv_CPP11_OR_GREATER_ || nssv_COMPILER_MSVC_VER >= 1910)
+
+#define nssv_CPP14_000 (nssv_CPP14_OR_GREATER)
+#define nssv_CPP17_000 (nssv_CPP17_OR_GREATER)
+
+// Presence of C++11 language features:
+
+#define nssv_HAVE_CONSTEXPR_11 nssv_CPP11_140
+#define nssv_HAVE_EXPLICIT_CONVERSION nssv_CPP11_140
+#define nssv_HAVE_INLINE_NAMESPACE nssv_CPP11_140
+#define nssv_HAVE_NOEXCEPT nssv_CPP11_140
+#define nssv_HAVE_NULLPTR nssv_CPP11_100
+#define nssv_HAVE_REF_QUALIFIER nssv_CPP11_140
+#define nssv_HAVE_UNICODE_LITERALS nssv_CPP11_140
+#define nssv_HAVE_USER_DEFINED_LITERALS nssv_CPP11_140
+#define nssv_HAVE_WCHAR16_T nssv_CPP11_100
+#define nssv_HAVE_WCHAR32_T nssv_CPP11_100
+
+#if ! ( ( nssv_CPP11_OR_GREATER && nssv_COMPILER_CLANG_VERSION ) || nssv_BETWEEN( nssv_COMPILER_CLANG_VERSION, 300, 400 ) )
+# define nssv_HAVE_STD_DEFINED_LITERALS nssv_CPP11_140
+#else
+# define nssv_HAVE_STD_DEFINED_LITERALS 0
+#endif
+
+// Presence of C++14 language features:
+
+#define nssv_HAVE_CONSTEXPR_14 nssv_CPP14_000
+
+// Presence of C++17 language features:
+
+#define nssv_HAVE_NODISCARD nssv_CPP17_000
+
+// Presence of C++ library features:
+
+#define nssv_HAVE_STD_HASH nssv_CPP11_120
+
+// C++ feature usage:
+
+#if nssv_HAVE_CONSTEXPR_11
+# define nssv_constexpr constexpr
+#else
+# define nssv_constexpr /*constexpr*/
+#endif
+
+#if nssv_HAVE_CONSTEXPR_14
+# define nssv_constexpr14 constexpr
+#else
+# define nssv_constexpr14 /*constexpr*/
+#endif
+
+#if nssv_HAVE_EXPLICIT_CONVERSION
+# define nssv_explicit explicit
+#else
+# define nssv_explicit /*explicit*/
+#endif
+
+#if nssv_HAVE_INLINE_NAMESPACE
+# define nssv_inline_ns inline
+#else
+# define nssv_inline_ns /*inline*/
+#endif
+
+#if nssv_HAVE_NOEXCEPT
+# define nssv_noexcept noexcept
+#else
+# define nssv_noexcept /*noexcept*/
+#endif
+
+//#if nssv_HAVE_REF_QUALIFIER
+//# define nssv_ref_qual &
+//# define nssv_refref_qual &&
+//#else
+//# define nssv_ref_qual /*&*/
+//# define nssv_refref_qual /*&&*/
+//#endif
+
+#if nssv_HAVE_NULLPTR
+# define nssv_nullptr nullptr
+#else
+# define nssv_nullptr NULL
+#endif
+
+#if nssv_HAVE_NODISCARD
+# define nssv_nodiscard [[nodiscard]]
+#else
+# define nssv_nodiscard /*[[nodiscard]]*/
+#endif
+
+// Additional includes:
+
+#include <algorithm>
+#include <cassert>
+#include <iterator>
+#include <limits>
+#include <ostream>
+#include <string> // std::char_traits<>
+
+#if ! nssv_CONFIG_NO_EXCEPTIONS
+# include <stdexcept>
+#endif
+
+#if nssv_CPP11_OR_GREATER
+# include <type_traits>
+#endif
+
+// Clang, GNUC, MSVC warning suppression macros:
+
+#if defined(__clang__)
+# pragma clang diagnostic ignored "-Wreserved-user-defined-literal"
+# pragma clang diagnostic push
+# pragma clang diagnostic ignored "-Wuser-defined-literals"
+#elif defined(__GNUC__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wliteral-suffix"
+#endif // __clang__
+
+#if nssv_COMPILER_MSVC_VERSION >= 140
+# define nssv_SUPPRESS_MSGSL_WARNING(expr) [[gsl::suppress(expr)]]
+# define nssv_SUPPRESS_MSVC_WARNING(code, descr) __pragma(warning(suppress: code) )
+# define nssv_DISABLE_MSVC_WARNINGS(codes) __pragma(warning(push)) __pragma(warning(disable: codes))
+#else
+# define nssv_SUPPRESS_MSGSL_WARNING(expr)
+# define nssv_SUPPRESS_MSVC_WARNING(code, descr)
+# define nssv_DISABLE_MSVC_WARNINGS(codes)
+#endif
+
+#if defined(__clang__)
+# define nssv_RESTORE_WARNINGS() _Pragma("clang diagnostic pop")
+#elif defined(__GNUC__)
+# define nssv_RESTORE_WARNINGS() _Pragma("GCC diagnostic pop")
+#elif nssv_COMPILER_MSVC_VERSION >= 140
+# define nssv_RESTORE_WARNINGS() __pragma(warning(pop ))
+#else
+# define nssv_RESTORE_WARNINGS()
+#endif
+
+// Suppress the following MSVC (GSL) warnings:
+// - C4455, non-gsl : 'operator ""sv': literal suffix identifiers that do not
+// start with an underscore are reserved
+// - C26472, gsl::t.1 : don't use a static_cast for arithmetic conversions;
+// use brace initialization, gsl::narrow_cast or gsl::narow
+// - C26481: gsl::b.1 : don't use pointer arithmetic. Use span instead
+
+nssv_DISABLE_MSVC_WARNINGS( 4455 26481 26472 )
+//nssv_DISABLE_CLANG_WARNINGS( "-Wuser-defined-literals" )
+//nssv_DISABLE_GNUC_WARNINGS( -Wliteral-suffix )
+
+namespace nonstd { namespace sv_lite {
+
+#if nssv_CPP11_OR_GREATER
+
+namespace detail {
+
+#if nssv_CPP14_OR_GREATER
+
+template< typename CharT >
+inline constexpr std::size_t length( CharT * s, std::size_t result = 0 )
+{
+ CharT * v = s;
+ std::size_t r = result;
+ while ( *v != '\0' ) {
+ ++v;
+ ++r;
+ }
+ return r;
+}
+
+#else // nssv_CPP14_OR_GREATER
+
+// Expect tail call optimization to make length() non-recursive:
+
+template< typename CharT >
+inline constexpr std::size_t length( CharT * s, std::size_t result = 0 )
+{
+ return *s == '\0' ? result : length( s + 1, result + 1 );
+}
+
+#endif // nssv_CPP14_OR_GREATER
+
+} // namespace detail
+
+#endif // nssv_CPP11_OR_GREATER
+
+template
+<
+ class CharT,
+ class Traits = std::char_traits<CharT>
+>
+class basic_string_view;
+
+//
+// basic_string_view:
+//
+
+template
+<
+ class CharT,
+ class Traits /* = std::char_traits<CharT> */
+>
+class basic_string_view
+{
+public:
+ // Member types:
+
+ typedef Traits traits_type;
+ typedef CharT value_type;
+
+ typedef CharT * pointer;
+ typedef CharT const * const_pointer;
+ typedef CharT & reference;
+ typedef CharT const & const_reference;
+
+ typedef const_pointer iterator;
+ typedef const_pointer const_iterator;
+ typedef std::reverse_iterator< const_iterator > reverse_iterator;
+ typedef std::reverse_iterator< const_iterator > const_reverse_iterator;
+
+ typedef std::size_t size_type;
+ typedef std::ptrdiff_t difference_type;
+
+ // 24.4.2.1 Construction and assignment:
+
+ nssv_constexpr basic_string_view() nssv_noexcept
+ : data_( nssv_nullptr )
+ , size_( 0 )
+ {}
+
+#if nssv_CPP11_OR_GREATER
+ nssv_constexpr basic_string_view( basic_string_view const & other ) nssv_noexcept = default;
+#else
+ nssv_constexpr basic_string_view( basic_string_view const & other ) nssv_noexcept
+ : data_( other.data_)
+ , size_( other.size_)
+ {}
+#endif
+
+ nssv_constexpr basic_string_view( CharT const * s, size_type count ) nssv_noexcept // non-standard noexcept
+ : data_( s )
+ , size_( count )
+ {}
+
+ nssv_constexpr basic_string_view( CharT const * s) nssv_noexcept // non-standard noexcept
+ : data_( s )
+#if nssv_CPP17_OR_GREATER
+ , size_( Traits::length(s) )
+#elif nssv_CPP11_OR_GREATER
+ , size_( detail::length(s) )
+#else
+ , size_( Traits::length(s) )
+#endif
+ {}
+
+ // Assignment:
+
+#if nssv_CPP11_OR_GREATER
+ nssv_constexpr14 basic_string_view & operator=( basic_string_view const & other ) nssv_noexcept = default;
+#else
+ nssv_constexpr14 basic_string_view & operator=( basic_string_view const & other ) nssv_noexcept
+ {
+ data_ = other.data_;
+ size_ = other.size_;
+ return *this;
+ }
+#endif
+
+ // 24.4.2.2 Iterator support:
+
+ nssv_constexpr const_iterator begin() const nssv_noexcept { return data_; }
+ nssv_constexpr const_iterator end() const nssv_noexcept { return data_ + size_; }
+
+ nssv_constexpr const_iterator cbegin() const nssv_noexcept { return begin(); }
+ nssv_constexpr const_iterator cend() const nssv_noexcept { return end(); }
+
+ nssv_constexpr const_reverse_iterator rbegin() const nssv_noexcept { return const_reverse_iterator( end() ); }
+ nssv_constexpr const_reverse_iterator rend() const nssv_noexcept { return const_reverse_iterator( begin() ); }
+
+ nssv_constexpr const_reverse_iterator crbegin() const nssv_noexcept { return rbegin(); }
+ nssv_constexpr const_reverse_iterator crend() const nssv_noexcept { return rend(); }
+
+ // 24.4.2.3 Capacity:
+
+ nssv_constexpr size_type size() const nssv_noexcept { return size_; }
+ nssv_constexpr size_type length() const nssv_noexcept { return size_; }
+ nssv_constexpr size_type max_size() const nssv_noexcept { return (std::numeric_limits< size_type >::max)(); }
+
+ // since C++20
+ nssv_nodiscard nssv_constexpr bool empty() const nssv_noexcept
+ {
+ return 0 == size_;
+ }
+
+ // 24.4.2.4 Element access:
+
+ nssv_constexpr const_reference operator[]( size_type pos ) const
+ {
+ return data_at( pos );
+ }
+
+ nssv_constexpr14 const_reference at( size_type pos ) const
+ {
+#if nssv_CONFIG_NO_EXCEPTIONS
+ assert( pos < size() );
+#else
+ if ( pos >= size() )
+ {
+ throw std::out_of_range("nonstd::string_view::at()");
+ }
+#endif
+ return data_at( pos );
+ }
+
+ nssv_constexpr const_reference front() const { return data_at( 0 ); }
+ nssv_constexpr const_reference back() const { return data_at( size() - 1 ); }
+
+ nssv_constexpr const_pointer data() const nssv_noexcept { return data_; }
+
+ // 24.4.2.5 Modifiers:
+
+ nssv_constexpr14 void remove_prefix( size_type n )
+ {
+ assert( n <= size() );
+ data_ += n;
+ size_ -= n;
+ }
+
+ nssv_constexpr14 void remove_suffix( size_type n )
+ {
+ assert( n <= size() );
+ size_ -= n;
+ }
+
+ nssv_constexpr14 void swap( basic_string_view & other ) nssv_noexcept
+ {
+ using std::swap;
+ swap( data_, other.data_ );
+ swap( size_, other.size_ );
+ }
+
+ // 24.4.2.6 String operations:
+
+ size_type copy( CharT * dest, size_type n, size_type pos = 0 ) const
+ {
+#if nssv_CONFIG_NO_EXCEPTIONS
+ assert( pos <= size() );
+#else
+ if ( pos > size() )
+ {
+ throw std::out_of_range("nonstd::string_view::copy()");
+ }
+#endif
+ const size_type rlen = (std::min)( n, size() - pos );
+
+ (void) Traits::copy( dest, data() + pos, rlen );
+
+ return rlen;
+ }
+
+ nssv_constexpr14 basic_string_view substr( size_type pos = 0, size_type n = npos ) const
+ {
+#if nssv_CONFIG_NO_EXCEPTIONS
+ assert( pos <= size() );
+#else
+ if ( pos > size() )
+ {
+ throw std::out_of_range("nonstd::string_view::substr()");
+ }
+#endif
+ return basic_string_view( data() + pos, (std::min)( n, size() - pos ) );
+ }
+
+ // compare(), 6x:
+
+ nssv_constexpr14 int compare( basic_string_view other ) const nssv_noexcept // (1)
+ {
+ if ( const int result = Traits::compare( data(), other.data(), (std::min)( size(), other.size() ) ) )
+ {
+ return result;
+ }
+
+ return size() == other.size() ? 0 : size() < other.size() ? -1 : 1;
+ }
+
+ nssv_constexpr int compare( size_type pos1, size_type n1, basic_string_view other ) const // (2)
+ {
+ return substr( pos1, n1 ).compare( other );
+ }
+
+ nssv_constexpr int compare( size_type pos1, size_type n1, basic_string_view other, size_type pos2, size_type n2 ) const // (3)
+ {
+ return substr( pos1, n1 ).compare( other.substr( pos2, n2 ) );
+ }
+
+ nssv_constexpr int compare( CharT const * s ) const // (4)
+ {
+ return compare( basic_string_view( s ) );
+ }
+
+ nssv_constexpr int compare( size_type pos1, size_type n1, CharT const * s ) const // (5)
+ {
+ return substr( pos1, n1 ).compare( basic_string_view( s ) );
+ }
+
+ nssv_constexpr int compare( size_type pos1, size_type n1, CharT const * s, size_type n2 ) const // (6)
+ {
+ return substr( pos1, n1 ).compare( basic_string_view( s, n2 ) );
+ }
+
+ // 24.4.2.7 Searching:
+
+ // starts_with(), 3x, since C++20:
+
+ nssv_constexpr bool starts_with( basic_string_view v ) const nssv_noexcept // (1)
+ {
+ return size() >= v.size() && compare( 0, v.size(), v ) == 0;
+ }
+
+ nssv_constexpr bool starts_with( CharT c ) const nssv_noexcept // (2)
+ {
+ return starts_with( basic_string_view( &c, 1 ) );
+ }
+
+ nssv_constexpr bool starts_with( CharT const * s ) const // (3)
+ {
+ return starts_with( basic_string_view( s ) );
+ }
+
+ // ends_with(), 3x, since C++20:
+
+ nssv_constexpr bool ends_with( basic_string_view v ) const nssv_noexcept // (1)
+ {
+ return size() >= v.size() && compare( size() - v.size(), npos, v ) == 0;
+ }
+
+ nssv_constexpr bool ends_with( CharT c ) const nssv_noexcept // (2)
+ {
+ return ends_with( basic_string_view( &c, 1 ) );
+ }
+
+ nssv_constexpr bool ends_with( CharT const * s ) const // (3)
+ {
+ return ends_with( basic_string_view( s ) );
+ }
+
+ // find(), 4x:
+
+ nssv_constexpr14 size_type find( basic_string_view v, size_type pos = 0 ) const nssv_noexcept // (1)
+ {
+ return assert( v.size() == 0 || v.data() != nssv_nullptr )
+ , pos >= size()
+ ? npos
+ : to_pos( std::search( cbegin() + pos, cend(), v.cbegin(), v.cend(), Traits::eq ) );
+ }
+
+ nssv_constexpr14 size_type find( CharT c, size_type pos = 0 ) const nssv_noexcept // (2)
+ {
+ return find( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr14 size_type find( CharT const * s, size_type pos, size_type n ) const // (3)
+ {
+ return find( basic_string_view( s, n ), pos );
+ }
+
+ nssv_constexpr14 size_type find( CharT const * s, size_type pos = 0 ) const // (4)
+ {
+ return find( basic_string_view( s ), pos );
+ }
+
+ // rfind(), 4x:
+
+ nssv_constexpr14 size_type rfind( basic_string_view v, size_type pos = npos ) const nssv_noexcept // (1)
+ {
+ if ( size() < v.size() )
+ {
+ return npos;
+ }
+
+ if ( v.empty() )
+ {
+ return (std::min)( size(), pos );
+ }
+
+ const_iterator last = cbegin() + (std::min)( size() - v.size(), pos ) + v.size();
+ const_iterator result = std::find_end( cbegin(), last, v.cbegin(), v.cend(), Traits::eq );
+
+ return result != last ? size_type( result - cbegin() ) : npos;
+ }
+
+ nssv_constexpr14 size_type rfind( CharT c, size_type pos = npos ) const nssv_noexcept // (2)
+ {
+ return rfind( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr14 size_type rfind( CharT const * s, size_type pos, size_type n ) const // (3)
+ {
+ return rfind( basic_string_view( s, n ), pos );
+ }
+
+ nssv_constexpr14 size_type rfind( CharT const * s, size_type pos = npos ) const // (4)
+ {
+ return rfind( basic_string_view( s ), pos );
+ }
+
+ // find_first_of(), 4x:
+
+ nssv_constexpr size_type find_first_of( basic_string_view v, size_type pos = 0 ) const nssv_noexcept // (1)
+ {
+ return pos >= size()
+ ? npos
+ : to_pos( std::find_first_of( cbegin() + pos, cend(), v.cbegin(), v.cend(), Traits::eq ) );
+ }
+
+ nssv_constexpr size_type find_first_of( CharT c, size_type pos = 0 ) const nssv_noexcept // (2)
+ {
+ return find_first_of( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr size_type find_first_of( CharT const * s, size_type pos, size_type n ) const // (3)
+ {
+ return find_first_of( basic_string_view( s, n ), pos );
+ }
+
+ nssv_constexpr size_type find_first_of( CharT const * s, size_type pos = 0 ) const // (4)
+ {
+ return find_first_of( basic_string_view( s ), pos );
+ }
+
+ // find_last_of(), 4x:
+
+ nssv_constexpr size_type find_last_of( basic_string_view v, size_type pos = npos ) const nssv_noexcept // (1)
+ {
+ return empty()
+ ? npos
+ : pos >= size()
+ ? find_last_of( v, size() - 1 )
+ : to_pos( std::find_first_of( const_reverse_iterator( cbegin() + pos + 1 ), crend(), v.cbegin(), v.cend(), Traits::eq ) );
+ }
+
+ nssv_constexpr size_type find_last_of( CharT c, size_type pos = npos ) const nssv_noexcept // (2)
+ {
+ return find_last_of( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr size_type find_last_of( CharT const * s, size_type pos, size_type count ) const // (3)
+ {
+ return find_last_of( basic_string_view( s, count ), pos );
+ }
+
+ nssv_constexpr size_type find_last_of( CharT const * s, size_type pos = npos ) const // (4)
+ {
+ return find_last_of( basic_string_view( s ), pos );
+ }
+
+ // find_first_not_of(), 4x:
+
+ nssv_constexpr size_type find_first_not_of( basic_string_view v, size_type pos = 0 ) const nssv_noexcept // (1)
+ {
+ return pos >= size()
+ ? npos
+ : to_pos( std::find_if( cbegin() + pos, cend(), not_in_view( v ) ) );
+ }
+
+ nssv_constexpr size_type find_first_not_of( CharT c, size_type pos = 0 ) const nssv_noexcept // (2)
+ {
+ return find_first_not_of( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr size_type find_first_not_of( CharT const * s, size_type pos, size_type count ) const // (3)
+ {
+ return find_first_not_of( basic_string_view( s, count ), pos );
+ }
+
+ nssv_constexpr size_type find_first_not_of( CharT const * s, size_type pos = 0 ) const // (4)
+ {
+ return find_first_not_of( basic_string_view( s ), pos );
+ }
+
+ // find_last_not_of(), 4x:
+
+ nssv_constexpr size_type find_last_not_of( basic_string_view v, size_type pos = npos ) const nssv_noexcept // (1)
+ {
+ return empty()
+ ? npos
+ : pos >= size()
+ ? find_last_not_of( v, size() - 1 )
+ : to_pos( std::find_if( const_reverse_iterator( cbegin() + pos + 1 ), crend(), not_in_view( v ) ) );
+ }
+
+ nssv_constexpr size_type find_last_not_of( CharT c, size_type pos = npos ) const nssv_noexcept // (2)
+ {
+ return find_last_not_of( basic_string_view( &c, 1 ), pos );
+ }
+
+ nssv_constexpr size_type find_last_not_of( CharT const * s, size_type pos, size_type count ) const // (3)
+ {
+ return find_last_not_of( basic_string_view( s, count ), pos );
+ }
+
+ nssv_constexpr size_type find_last_not_of( CharT const * s, size_type pos = npos ) const // (4)
+ {
+ return find_last_not_of( basic_string_view( s ), pos );
+ }
+
+ // Constants:
+
+#if nssv_CPP17_OR_GREATER
+ static nssv_constexpr size_type npos = size_type(-1);
+#elif nssv_CPP11_OR_GREATER
+ enum : size_type { npos = size_type(-1) };
+#else
+ enum { npos = size_type(-1) };
+#endif
+
+private:
+ struct not_in_view
+ {
+ const basic_string_view v;
+
+ nssv_constexpr explicit not_in_view( basic_string_view v_ ) : v( v_ ) {}
+
+ nssv_constexpr bool operator()( CharT c ) const
+ {
+ return npos == v.find_first_of( c );
+ }
+ };
+
+ nssv_constexpr size_type to_pos( const_iterator it ) const
+ {
+ return it == cend() ? npos : size_type( it - cbegin() );
+ }
+
+ nssv_constexpr size_type to_pos( const_reverse_iterator it ) const
+ {
+ return it == crend() ? npos : size_type( crend() - it - 1 );
+ }
+
+ nssv_constexpr const_reference data_at( size_type pos ) const
+ {
+#if nssv_BETWEEN( nssv_COMPILER_GNUC_VERSION, 1, 500 )
+ return data_[pos];
+#else
+ return assert( pos < size() ), data_[pos];
+#endif
+ }
+
+private:
+ const_pointer data_;
+ size_type size_;
+
+public:
+#if nssv_CONFIG_CONVERSION_STD_STRING_CLASS_METHODS
+
+ template< class Allocator >
+ basic_string_view( std::basic_string<CharT, Traits, Allocator> const & s ) nssv_noexcept
+ : data_( s.data() )
+ , size_( s.size() )
+ {}
+
+#if nssv_HAVE_EXPLICIT_CONVERSION
+
+ template< class Allocator >
+ explicit operator std::basic_string<CharT, Traits, Allocator>() const
+ {
+ return to_string( Allocator() );
+ }
+
+#endif // nssv_HAVE_EXPLICIT_CONVERSION
+
+#if nssv_CPP11_OR_GREATER
+
+ template< class Allocator = std::allocator<CharT> >
+ std::basic_string<CharT, Traits, Allocator>
+ to_string( Allocator const & a = Allocator() ) const
+ {
+ return std::basic_string<CharT, Traits, Allocator>( begin(), end(), a );
+ }
+
+#else
+
+ std::basic_string<CharT, Traits>
+ to_string() const
+ {
+ return std::basic_string<CharT, Traits>( begin(), end() );
+ }
+
+ template< class Allocator >
+ std::basic_string<CharT, Traits, Allocator>
+ to_string( Allocator const & a ) const
+ {
+ return std::basic_string<CharT, Traits, Allocator>( begin(), end(), a );
+ }
+
+#endif // nssv_CPP11_OR_GREATER
+
+#endif // nssv_CONFIG_CONVERSION_STD_STRING_CLASS_METHODS
+};
+
+//
+// Non-member functions:
+//
+
+// 24.4.3 Non-member comparison functions:
+// lexicographically compare two string views (function template):
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator== (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) == 0 ; }
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator!= (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) != 0 ; }
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator< (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) < 0 ; }
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator<= (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) <= 0 ; }
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator> (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) > 0 ; }
+
+template< class CharT, class Traits >
+nssv_constexpr bool operator>= (
+ basic_string_view <CharT, Traits> lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) >= 0 ; }
+
+// Let S be basic_string_view<CharT, Traits>, and sv be an instance of S.
+// Implementations shall provide sufficient additional overloads marked
+// constexpr and noexcept so that an object t with an implicit conversion
+// to S can be compared according to Table 67.
+
+#if ! nssv_CPP11_OR_GREATER || nssv_BETWEEN( nssv_COMPILER_MSVC_VERSION, 100, 141 )
+
+// accomodate for older compilers:
+
+// ==
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator==(
+ basic_string_view<CharT, Traits> lhs,
+ CharT const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) == 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator==(
+ CharT const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) == 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator==(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.size() == rhs.size() && lhs.compare( rhs ) == 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator==(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return lhs.size() == rhs.size() && lhs.compare( rhs ) == 0; }
+
+// !=
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator!=(
+ basic_string_view<CharT, Traits> lhs,
+ char const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) != 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator!=(
+ char const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) != 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator!=(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.size() != rhs.size() && lhs.compare( rhs ) != 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator!=(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return lhs.size() != rhs.size() || rhs.compare( lhs ) != 0; }
+
+// <
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<(
+ basic_string_view<CharT, Traits> lhs,
+ char const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) < 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<(
+ char const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) > 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) < 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return rhs.compare( lhs ) > 0; }
+
+// <=
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<=(
+ basic_string_view<CharT, Traits> lhs,
+ char const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) <= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<=(
+ char const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) >= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<=(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) <= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator<=(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return rhs.compare( lhs ) >= 0; }
+
+// >
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>(
+ basic_string_view<CharT, Traits> lhs,
+ char const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) > 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>(
+ char const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) < 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) > 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return rhs.compare( lhs ) < 0; }
+
+// >=
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>=(
+ basic_string_view<CharT, Traits> lhs,
+ char const * rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) >= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>=(
+ char const * lhs,
+ basic_string_view<CharT, Traits> rhs ) nssv_noexcept
+{ return rhs.compare( lhs ) <= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>=(
+ basic_string_view<CharT, Traits> lhs,
+ std::basic_string<CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) >= 0; }
+
+template< class CharT, class Traits>
+nssv_constexpr bool operator>=(
+ std::basic_string<CharT, Traits> rhs,
+ basic_string_view<CharT, Traits> lhs ) nssv_noexcept
+{ return rhs.compare( lhs ) <= 0; }
+
+#else // newer compilers:
+
+#define nssv_BASIC_STRING_VIEW_I(T,U) typename std::decay< basic_string_view<T,U> >::type
+
+#if nssv_BETWEEN( nssv_COMPILER_MSVC_VERSION, 140, 150 )
+# define nssv_MSVC_ORDER(x) , int=x
+#else
+# define nssv_MSVC_ORDER(x) /*, int=x*/
+#endif
+
+// ==
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator==(
+ basic_string_view <CharT, Traits> lhs,
+ nssv_BASIC_STRING_VIEW_I(CharT, Traits) rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) == 0; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator==(
+ nssv_BASIC_STRING_VIEW_I(CharT, Traits) lhs,
+ basic_string_view <CharT, Traits> rhs ) nssv_noexcept
+{ return lhs.size() == rhs.size() && lhs.compare( rhs ) == 0; }
+
+// !=
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator!= (
+ basic_string_view < CharT, Traits > lhs,
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) rhs ) nssv_noexcept
+{ return lhs.size() != rhs.size() || lhs.compare( rhs ) != 0 ; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator!= (
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) lhs,
+ basic_string_view < CharT, Traits > rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) != 0 ; }
+
+// <
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator< (
+ basic_string_view < CharT, Traits > lhs,
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) < 0 ; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator< (
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) lhs,
+ basic_string_view < CharT, Traits > rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) < 0 ; }
+
+// <=
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator<= (
+ basic_string_view < CharT, Traits > lhs,
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) <= 0 ; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator<= (
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) lhs,
+ basic_string_view < CharT, Traits > rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) <= 0 ; }
+
+// >
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator> (
+ basic_string_view < CharT, Traits > lhs,
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) > 0 ; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator> (
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) lhs,
+ basic_string_view < CharT, Traits > rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) > 0 ; }
+
+// >=
+
+template< class CharT, class Traits nssv_MSVC_ORDER(1) >
+nssv_constexpr bool operator>= (
+ basic_string_view < CharT, Traits > lhs,
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) >= 0 ; }
+
+template< class CharT, class Traits nssv_MSVC_ORDER(2) >
+nssv_constexpr bool operator>= (
+ nssv_BASIC_STRING_VIEW_I( CharT, Traits ) lhs,
+ basic_string_view < CharT, Traits > rhs ) nssv_noexcept
+{ return lhs.compare( rhs ) >= 0 ; }
+
+#undef nssv_MSVC_ORDER
+#undef nssv_BASIC_STRING_VIEW_I
+
+#endif // compiler-dependent approach to comparisons
+
+// 24.4.4 Inserters and extractors:
+
+namespace detail {
+
+template< class Stream >
+void write_padding( Stream & os, std::streamsize n )
+{
+ for ( std::streamsize i = 0; i < n; ++i )
+ os.rdbuf()->sputc( os.fill() );
+}
+
+template< class Stream, class View >
+Stream & write_to_stream( Stream & os, View const & sv )
+{
+ typename Stream::sentry sentry( os );
+
+ if ( !os )
+ return os;
+
+ const std::streamsize length = static_cast<std::streamsize>( sv.length() );
+
+ // Whether, and how, to pad:
+ const bool pad = ( length < os.width() );
+ const bool left_pad = pad && ( os.flags() & std::ios_base::adjustfield ) == std::ios_base::right;
+
+ if ( left_pad )
+ write_padding( os, os.width() - length );
+
+ // Write span characters:
+ os.rdbuf()->sputn( sv.begin(), length );
+
+ if ( pad && !left_pad )
+ write_padding( os, os.width() - length );
+
+ // Reset output stream width:
+ os.width( 0 );
+
+ return os;
+}
+
+} // namespace detail
+
+template< class CharT, class Traits >
+std::basic_ostream<CharT, Traits> &
+operator<<(
+ std::basic_ostream<CharT, Traits>& os,
+ basic_string_view <CharT, Traits> sv )
+{
+ return detail::write_to_stream( os, sv );
+}
+
+// Several typedefs for common character types are provided:
+
+typedef basic_string_view<char> string_view;
+typedef basic_string_view<wchar_t> wstring_view;
+#if nssv_HAVE_WCHAR16_T
+typedef basic_string_view<char16_t> u16string_view;
+typedef basic_string_view<char32_t> u32string_view;
+#endif
+
+}} // namespace nonstd::sv_lite
+
+//
+// 24.4.6 Suffix for basic_string_view literals:
+//
+
+#if nssv_HAVE_USER_DEFINED_LITERALS
+
+namespace nonstd {
+nssv_inline_ns namespace literals {
+nssv_inline_ns namespace string_view_literals {
+
+#if nssv_CONFIG_STD_SV_OPERATOR && nssv_HAVE_STD_DEFINED_LITERALS
+
+nssv_constexpr nonstd::sv_lite::string_view operator "" sv( const char* str, size_t len ) nssv_noexcept // (1)
+{
+ return nonstd::sv_lite::string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::u16string_view operator "" sv( const char16_t* str, size_t len ) nssv_noexcept // (2)
+{
+ return nonstd::sv_lite::u16string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::u32string_view operator "" sv( const char32_t* str, size_t len ) nssv_noexcept // (3)
+{
+ return nonstd::sv_lite::u32string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::wstring_view operator "" sv( const wchar_t* str, size_t len ) nssv_noexcept // (4)
+{
+ return nonstd::sv_lite::wstring_view{ str, len };
+}
+
+#endif // nssv_CONFIG_STD_SV_OPERATOR && nssv_HAVE_STD_DEFINED_LITERALS
+
+#if nssv_CONFIG_USR_SV_OPERATOR
+
+nssv_constexpr nonstd::sv_lite::string_view operator "" _sv( const char* str, size_t len ) nssv_noexcept // (1)
+{
+ return nonstd::sv_lite::string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::u16string_view operator "" _sv( const char16_t* str, size_t len ) nssv_noexcept // (2)
+{
+ return nonstd::sv_lite::u16string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::u32string_view operator "" _sv( const char32_t* str, size_t len ) nssv_noexcept // (3)
+{
+ return nonstd::sv_lite::u32string_view{ str, len };
+}
+
+nssv_constexpr nonstd::sv_lite::wstring_view operator "" _sv( const wchar_t* str, size_t len ) nssv_noexcept // (4)
+{
+ return nonstd::sv_lite::wstring_view{ str, len };
+}
+
+#endif // nssv_CONFIG_USR_SV_OPERATOR
+
+}}} // namespace nonstd::literals::string_view_literals
+
+#endif
+
+//
+// Extensions for std::string:
+//
+
+#if nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+
+namespace nonstd {
+namespace sv_lite {
+
+// Exclude MSVC 14 (19.00): it yields ambiguous to_string():
+
+#if nssv_CPP11_OR_GREATER && nssv_COMPILER_MSVC_VERSION != 140
+
+template< class CharT, class Traits, class Allocator = std::allocator<CharT> >
+std::basic_string<CharT, Traits, Allocator>
+to_string( basic_string_view<CharT, Traits> v, Allocator const & a = Allocator() )
+{
+ return std::basic_string<CharT,Traits, Allocator>( v.begin(), v.end(), a );
+}
+
+#else
+
+template< class CharT, class Traits >
+std::basic_string<CharT, Traits>
+to_string( basic_string_view<CharT, Traits> v )
+{
+ return std::basic_string<CharT, Traits>( v.begin(), v.end() );
+}
+
+template< class CharT, class Traits, class Allocator >
+std::basic_string<CharT, Traits, Allocator>
+to_string( basic_string_view<CharT, Traits> v, Allocator const & a )
+{
+ return std::basic_string<CharT, Traits, Allocator>( v.begin(), v.end(), a );
+}
+
+#endif // nssv_CPP11_OR_GREATER
+
+template< class CharT, class Traits, class Allocator >
+basic_string_view<CharT, Traits>
+to_string_view( std::basic_string<CharT, Traits, Allocator> const & s )
+{
+ return basic_string_view<CharT, Traits>( s.data(), s.size() );
+}
+
+}} // namespace nonstd::sv_lite
+
+#endif // nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+
+//
+// make types and algorithms available in namespace nonstd:
+//
+
+namespace nonstd {
+
+using sv_lite::basic_string_view;
+using sv_lite::string_view;
+using sv_lite::wstring_view;
+
+#if nssv_HAVE_WCHAR16_T
+using sv_lite::u16string_view;
+#endif
+#if nssv_HAVE_WCHAR32_T
+using sv_lite::u32string_view;
+#endif
+
+// literal "sv"
+
+using sv_lite::operator==;
+using sv_lite::operator!=;
+using sv_lite::operator<;
+using sv_lite::operator<=;
+using sv_lite::operator>;
+using sv_lite::operator>=;
+
+using sv_lite::operator<<;
+
+#if nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+using sv_lite::to_string;
+using sv_lite::to_string_view;
+#endif
+
+} // namespace nonstd
+
+// 24.4.5 Hash support (C++11):
+
+// Note: The hash value of a string view object is equal to the hash value of
+// the corresponding string object.
+
+#if nssv_HAVE_STD_HASH
+
+#include <functional>
+
+namespace std {
+
+template<>
+struct hash< nonstd::string_view >
+{
+public:
+ std::size_t operator()( nonstd::string_view v ) const nssv_noexcept
+ {
+ return std::hash<std::string>()( std::string( v.data(), v.size() ) );
+ }
+};
+
+template<>
+struct hash< nonstd::wstring_view >
+{
+public:
+ std::size_t operator()( nonstd::wstring_view v ) const nssv_noexcept
+ {
+ return std::hash<std::wstring>()( std::wstring( v.data(), v.size() ) );
+ }
+};
+
+template<>
+struct hash< nonstd::u16string_view >
+{
+public:
+ std::size_t operator()( nonstd::u16string_view v ) const nssv_noexcept
+ {
+ return std::hash<std::u16string>()( std::u16string( v.data(), v.size() ) );
+ }
+};
+
+template<>
+struct hash< nonstd::u32string_view >
+{
+public:
+ std::size_t operator()( nonstd::u32string_view v ) const nssv_noexcept
+ {
+ return std::hash<std::u32string>()( std::u32string( v.data(), v.size() ) );
+ }
+};
+
+} // namespace std
+
+#endif // nssv_HAVE_STD_HASH
+
+nssv_RESTORE_WARNINGS()
+
+#endif // nssv_HAVE_STD_STRING_VIEW
+#endif // NONSTD_SV_LITE_H_INCLUDED
projects / ceph.git / blobdiff