Squashed 'deps/inja/' content from commit 811e173

git-subtree-dir: deps/inja
git-subtree-split: 811e1730e13bca4ea1805a42d5f0a4b5c91046e1

1 files changed, 1416 insertions, 0 deletions

diff --git a/include/inja/string_view.hpp b/include/inja/string_view.hpp
new file mode 100644
index 0000000..2bb50c9
--- /dev/null
+++ b/include/inja/string_view.hpp
@@ -0,0 +1,1416 @@
+// Copyright 2017-2019 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 string_view_literals
+} // namespace literals
+
+#endif // nssv_CONFIG_USR_SV_OPERATOR
+
+} // namespace nonstd
+
+#endif // nssv_CONFIG_CONVERSION_STD_STRING_FREE_FUNCTIONS
+
+namespace nonstd {
+
+using std::basic_string_view;
+using std::string_view;
+using std::u16string_view;
+using std::u32string_view;
+using std::wstring_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 (Visual Studio 6.0)
+// MSVC++ 7.0  _MSC_VER == 1300 (Visual Studio .NET 2002)
+// MSVC++ 7.1  _MSC_VER == 1310 (Visual Studio .NET 2003)
+// MSVC++ 8.0  _MSC_VER == 1400 (Visual Studio 2005)
+// MSVC++ 9.0  _MSC_VER == 1500 (Visual Studio 2008)
+// MSVC++ 10.0 _MSC_VER == 1600 (Visual Studio 2010)
+// MSVC++ 11.0 _MSC_VER == 1700 (Visual Studio 2012)
+// MSVC++ 12.0 _MSC_VER == 1800 (Visual Studio 2013)
+// MSVC++ 14.0 _MSC_VER == 1900 (Visual Studio 2015)
+// MSVC++ 14.1 _MSC_VER >= 1910 (Visual Studio 2017)
+
+#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 {
+
+  // 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);
+  }
+
+  } // 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, 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() && 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 sv_lite
+} // 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
+
+#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 sv_lite
+} // namespace nonstd
+
+#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