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 // Formatting library for C++ - range and tuple support
 //
 // Copyright (c) 2012 - present, Victor Zverovich and {fmt} contributors
 // All rights reserved.
 //
 // For the license information refer to format.h.
 
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
 
 #ifndef FMT_MODULE
 #  include <initializer_list>
 #  include <iterator>
 #  include <string>
 #  include <tuple>
 #  include <type_traits>
 #  include <utility>
 #endif
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
 FMT_EXPORT
 enum class range_format { disabled, map, set, sequence, string, debug_string };
 
 namespace detail {
 
 template <typename T> class is_map {
   template <typename U> static auto check(U*) -> typename U::mapped_type;
   template <typename> static void check(...);
 
  public:
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 template <typename T> class is_set {
   template <typename U> static auto check(U*) -> typename U::key_type;
   template <typename> static void check(...);
 
  public:
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
 };
 
 // C array overload
 template <typename T, std::size_t N>
 auto range_begin(const T (&arr)[N]) -> const T* {
   return arr;
 }
 template <typename T, std::size_t N>
 auto range_end(const T (&arr)[N]) -> const T* {
   return arr + N;
 }
 
 template <typename T, typename Enable = void>
 struct has_member_fn_begin_end_t : std::false_type {};
 
 template <typename T>
 struct has_member_fn_begin_end_t<T, void_t<decltype(*std::declval<T>().begin()),
                                            decltype(std::declval<T>().end())>>
     : std::true_type {};
 
 // Member function overloads.
 template <typename T>
 auto range_begin(T&& rng) -> decltype(static_cast<T&&>(rng).begin()) {
   return static_cast<T&&>(rng).begin();
 }
 template <typename T>
 auto range_end(T&& rng) -> decltype(static_cast<T&&>(rng).end()) {
   return static_cast<T&&>(rng).end();
 }
 
 // ADL overloads. Only participate in overload resolution if member functions
 // are not found.
 template <typename T>
 auto range_begin(T&& rng)
     -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
                    decltype(begin(static_cast<T&&>(rng)))> {
   return begin(static_cast<T&&>(rng));
 }
 template <typename T>
 auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
                                        decltype(end(static_cast<T&&>(rng)))> {
   return end(static_cast<T&&>(rng));
 }
 
 template <typename T, typename Enable = void>
 struct has_const_begin_end : std::false_type {};
 template <typename T, typename Enable = void>
 struct has_mutable_begin_end : std::false_type {};
 
 template <typename T>
 struct has_const_begin_end<
     T, void_t<decltype(*detail::range_begin(
                   std::declval<const remove_cvref_t<T>&>())),
               decltype(detail::range_end(
                   std::declval<const remove_cvref_t<T>&>()))>>
     : std::true_type {};
 
 template <typename T>
 struct has_mutable_begin_end<
     T, void_t<decltype(*detail::range_begin(std::declval<T&>())),
               decltype(detail::range_end(std::declval<T&>())),
               // the extra int here is because older versions of MSVC don't
               // SFINAE properly unless there are distinct types
               int>> : std::true_type {};
 
 template <typename T, typename _ = void> struct is_range_ : std::false_type {};
 template <typename T>
 struct is_range_<T, void>
     : std::integral_constant<bool, (has_const_begin_end<T>::value ||
                                     has_mutable_begin_end<T>::value)> {};
 
 // tuple_size and tuple_element check.
 template <typename T> class is_tuple_like_ {
   template <typename U, typename V = typename std::remove_cv<U>::type>
   static auto check(U* p) -> decltype(std::tuple_size<V>::value, 0);
   template <typename> static void check(...);
 
  public:
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 // Check for integer_sequence
 #if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900
 template <typename T, T... N>
 using integer_sequence = std::integer_sequence<T, N...>;
 template <size_t... N> using index_sequence = std::index_sequence<N...>;
 template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
 #else
 template <typename T, T... N> struct integer_sequence {
   using value_type = T;
 
   static FMT_CONSTEXPR auto size() -> size_t { return sizeof...(N); }
 };
 
 template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
 
 template <typename T, size_t N, T... Ns>
 struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
 template <typename T, T... Ns>
 struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
 
 template <size_t N>
 using make_index_sequence = make_integer_sequence<size_t, N>;
 #endif
 
 template <typename T>
 using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
 
 template <typename T, typename C, bool = is_tuple_like_<T>::value>
 class is_tuple_formattable_ {
  public:
   static constexpr const bool value = false;
 };
 template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
   template <size_t... Is>
   static auto all_true(index_sequence<Is...>,
                        integer_sequence<bool, (Is >= 0)...>) -> std::true_type;
   static auto all_true(...) -> std::false_type;
 
   template <size_t... Is>
   static auto check(index_sequence<Is...>) -> decltype(all_true(
       index_sequence<Is...>{},
       integer_sequence<bool,
                        (is_formattable<typename std::tuple_element<Is, T>::type,
                                        C>::value)...>{}));
 
  public:
   static constexpr const bool value =
       decltype(check(tuple_index_sequence<T>{}))::value;
 };
 
 template <typename Tuple, typename F, size_t... Is>
 FMT_CONSTEXPR void for_each(index_sequence<Is...>, Tuple&& t, F&& f) {
   using std::get;
   // Using a free function get<Is>(Tuple) now.
   const int unused[] = {0, ((void)f(get<Is>(t)), 0)...};
   ignore_unused(unused);
 }
 
 template <typename Tuple, typename F>
 FMT_CONSTEXPR void for_each(Tuple&& t, F&& f) {
   for_each(tuple_index_sequence<remove_cvref_t<Tuple>>(),
            std::forward<Tuple>(t), std::forward<F>(f));
 }
 
 template <typename Tuple1, typename Tuple2, typename F, size_t... Is>
 void for_each2(index_sequence<Is...>, Tuple1&& t1, Tuple2&& t2, F&& f) {
   using std::get;
   const int unused[] = {0, ((void)f(get<Is>(t1), get<Is>(t2)), 0)...};
   ignore_unused(unused);
 }
 
 template <typename Tuple1, typename Tuple2, typename F>
 void for_each2(Tuple1&& t1, Tuple2&& t2, F&& f) {
   for_each2(tuple_index_sequence<remove_cvref_t<Tuple1>>(),
             std::forward<Tuple1>(t1), std::forward<Tuple2>(t2),
             std::forward<F>(f));
 }
 
 namespace tuple {
 // Workaround a bug in MSVC 2019 (v140).
 template <typename Char, typename... T>
 using result_t = std::tuple<formatter<remove_cvref_t<T>, Char>...>;
 
 using std::get;
 template <typename Tuple, typename Char, std::size_t... Is>
 auto get_formatters(index_sequence<Is...>)
     -> result_t<Char, decltype(get<Is>(std::declval<Tuple>()))...>;
 }  // namespace tuple
 
 #if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
 // Older MSVC doesn't get the reference type correctly for arrays.
 template <typename R> struct range_reference_type_impl {
   using type = decltype(*detail::range_begin(std::declval<R&>()));
 };
 
 template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
   using type = T&;
 };
 
 template <typename T>
 using range_reference_type = typename range_reference_type_impl<T>::type;
 #else
 template <typename Range>
 using range_reference_type =
     decltype(*detail::range_begin(std::declval<Range&>()));
 #endif
 
 // We don't use the Range's value_type for anything, but we do need the Range's
 // reference type, with cv-ref stripped.
 template <typename Range>
 using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
 
 template <typename Formatter>
 FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set)
     -> decltype(f.set_debug_format(set)) {
   f.set_debug_format(set);
 }
 template <typename Formatter>
 FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {}
 
 template <typename T>
 struct range_format_kind_
     : std::integral_constant<range_format,
                              std::is_same<uncvref_type<T>, T>::value
                                  ? range_format::disabled
                              : is_map<T>::value ? range_format::map
                              : is_set<T>::value ? range_format::set
                                                 : range_format::sequence> {};
 
 template <range_format K>
 using range_format_constant = std::integral_constant<range_format, K>;
 
 // These are not generic lambdas for compatibility with C++11.
 template <typename Char> struct parse_empty_specs {
   template <typename Formatter> FMT_CONSTEXPR void operator()(Formatter& f) {
     f.parse(ctx);
     detail::maybe_set_debug_format(f, true);
   }
   parse_context<Char>& ctx;
 };
 template <typename FormatContext> struct format_tuple_element {
   using char_type = typename FormatContext::char_type;
 
   template <typename T>
   void operator()(const formatter<T, char_type>& f, const T& v) {
     if (i > 0) ctx.advance_to(detail::copy<char_type>(separator, ctx.out()));
     ctx.advance_to(f.format(v, ctx));
     ++i;
   }
 
   int i;
   FormatContext& ctx;
   basic_string_view<char_type> separator;
 };
 
 }  // namespace detail
 
 template <typename T> struct is_tuple_like {
   static constexpr const bool value =
       detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
 };
 
 template <typename T, typename C> struct is_tuple_formattable {
   static constexpr const bool value =
       detail::is_tuple_formattable_<T, C>::value;
 };
 
 template <typename Tuple, typename Char>
 struct formatter<Tuple, Char,
                  enable_if_t<fmt::is_tuple_like<Tuple>::value &&
                              fmt::is_tuple_formattable<Tuple, Char>::value>> {
  private:
   decltype(detail::tuple::get_formatters<Tuple, Char>(
       detail::tuple_index_sequence<Tuple>())) formatters_;
 
   basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
   basic_string_view<Char> opening_bracket_ =
       detail::string_literal<Char, '('>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ')'>{};
 
  public:
   FMT_CONSTEXPR formatter() {}
 
   FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
     separator_ = sep;
   }
 
   FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
                                   basic_string_view<Char> close) {
     opening_bracket_ = open;
     closing_bracket_ = close;
   }
 
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     auto it = ctx.begin();
     auto end = ctx.end();
     if (it != end && detail::to_ascii(*it) == 'n') {
       ++it;
       set_brackets({}, {});
       set_separator({});
     }
     if (it != end && *it != '}') report_error("invalid format specifier");
     ctx.advance_to(it);
     detail::for_each(formatters_, detail::parse_empty_specs<Char>{ctx});
     return it;
   }
 
   template <typename FormatContext>
   auto format(const Tuple& value, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     ctx.advance_to(detail::copy<Char>(opening_bracket_, ctx.out()));
     detail::for_each2(
         formatters_, value,
         detail::format_tuple_element<FormatContext>{0, ctx, separator_});
     return detail::copy<Char>(closing_bracket_, ctx.out());
   }
 };
 
 template <typename T, typename Char> struct is_range {
   static constexpr const bool value =
       detail::is_range_<T>::value && !detail::has_to_string_view<T>::value;
 };
 
 namespace detail {
 
 template <typename Char, typename Element>
 using range_formatter_type = formatter<remove_cvref_t<Element>, Char>;
 
 template <typename R>
 using maybe_const_range =
     conditional_t<has_const_begin_end<R>::value, const R, R>;
 
 template <typename R, typename Char>
 struct is_formattable_delayed
     : is_formattable<uncvref_type<maybe_const_range<R>>, Char> {};
 }  // namespace detail
 
 template <typename...> struct conjunction : std::true_type {};
 template <typename P> struct conjunction<P> : P {};
 template <typename P1, typename... Pn>
 struct conjunction<P1, Pn...>
     : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
 
 template <typename T, typename Char, typename Enable = void>
 struct range_formatter;
 
 template <typename T, typename Char>
 struct range_formatter<
     T, Char,
     enable_if_t<conjunction<std::is_same<T, remove_cvref_t<T>>,
                             is_formattable<T, Char>>::value>> {
  private:
   detail::range_formatter_type<Char, T> underlying_;
   basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
   basic_string_view<Char> opening_bracket_ =
       detail::string_literal<Char, '['>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ']'>{};
   bool is_debug = false;
 
   template <typename Output, typename It, typename Sentinel, typename U = T,
             FMT_ENABLE_IF(std::is_same<U, Char>::value)>
   auto write_debug_string(Output& out, It it, Sentinel end) const -> Output {
     auto buf = basic_memory_buffer<Char>();
     for (; it != end; ++it) buf.push_back(*it);
     auto specs = format_specs();
     specs.set_type(presentation_type::debug);
     return detail::write<Char>(
         out, basic_string_view<Char>(buf.data(), buf.size()), specs);
   }
 
   template <typename Output, typename It, typename Sentinel, typename U = T,
             FMT_ENABLE_IF(!std::is_same<U, Char>::value)>
   auto write_debug_string(Output& out, It, Sentinel) const -> Output {
     return out;
   }
 
  public:
   FMT_CONSTEXPR range_formatter() {}
 
   FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type<Char, T>& {
     return underlying_;
   }
 
   FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
     separator_ = sep;
   }
 
   FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
                                   basic_string_view<Char> close) {
     opening_bracket_ = open;
     closing_bracket_ = close;
   }
 
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     auto it = ctx.begin();
     auto end = ctx.end();
     detail::maybe_set_debug_format(underlying_, true);
     if (it == end) return underlying_.parse(ctx);
 
     switch (detail::to_ascii(*it)) {
     case 'n':
       set_brackets({}, {});
       ++it;
       break;
     case '?':
       is_debug = true;
       set_brackets({}, {});
       ++it;
       if (it == end || *it != 's') report_error("invalid format specifier");
       FMT_FALLTHROUGH;
     case 's':
       if (!std::is_same<T, Char>::value)
         report_error("invalid format specifier");
       if (!is_debug) {
         set_brackets(detail::string_literal<Char, '"'>{},
                      detail::string_literal<Char, '"'>{});
         set_separator({});
         detail::maybe_set_debug_format(underlying_, false);
       }
       ++it;
       return it;
     }
 
     if (it != end && *it != '}') {
       if (*it != ':') report_error("invalid format specifier");
       detail::maybe_set_debug_format(underlying_, false);
       ++it;
     }
 
     ctx.advance_to(it);
     return underlying_.parse(ctx);
   }
 
   template <typename R, typename FormatContext>
   auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
     auto out = ctx.out();
     auto it = detail::range_begin(range);
     auto end = detail::range_end(range);
     if (is_debug) return write_debug_string(out, std::move(it), end);
 
     out = detail::copy<Char>(opening_bracket_, out);
     int i = 0;
     for (; it != end; ++it) {
       if (i > 0) out = detail::copy<Char>(separator_, out);
       ctx.advance_to(out);
       auto&& item = *it;  // Need an lvalue
       out = underlying_.format(item, ctx);
       ++i;
     }
     out = detail::copy<Char>(closing_bracket_, out);
     return out;
   }
 };
 
 FMT_EXPORT
 template <typename T, typename Char, typename Enable = void>
 struct range_format_kind
     : conditional_t<
           is_range<T, Char>::value, detail::range_format_kind_<T>,
           std::integral_constant<range_format, range_format::disabled>> {};
 
 template <typename R, typename Char>
 struct formatter<
     R, Char,
     enable_if_t<conjunction<
         bool_constant<
             range_format_kind<R, Char>::value != range_format::disabled &&
             range_format_kind<R, Char>::value != range_format::map &&
             range_format_kind<R, Char>::value != range_format::string &&
             range_format_kind<R, Char>::value != range_format::debug_string>,
         detail::is_formattable_delayed<R, Char>>::value>> {
  private:
   using range_type = detail::maybe_const_range<R>;
   range_formatter<detail::uncvref_type<range_type>, Char> range_formatter_;
 
  public:
   using nonlocking = void;
 
   FMT_CONSTEXPR formatter() {
     if (detail::const_check(range_format_kind<R, Char>::value !=
                             range_format::set))
       return;
     range_formatter_.set_brackets(detail::string_literal<Char, '{'>{},
                                   detail::string_literal<Char, '}'>{});
   }
 
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     return range_formatter_.parse(ctx);
   }
 
   template <typename FormatContext>
   auto format(range_type& range, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     return range_formatter_.format(range, ctx);
   }
 };
 
 // A map formatter.
 template <typename R, typename Char>
 struct formatter<
     R, Char,
     enable_if_t<conjunction<
         bool_constant<range_format_kind<R, Char>::value == range_format::map>,
         detail::is_formattable_delayed<R, Char>>::value>> {
  private:
   using map_type = detail::maybe_const_range<R>;
   using element_type = detail::uncvref_type<map_type>;
 
   decltype(detail::tuple::get_formatters<element_type, Char>(
       detail::tuple_index_sequence<element_type>())) formatters_;
   bool no_delimiters_ = false;
 
  public:
   FMT_CONSTEXPR formatter() {}
 
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     auto it = ctx.begin();
     auto end = ctx.end();
     if (it != end) {
       if (detail::to_ascii(*it) == 'n') {
         no_delimiters_ = true;
         ++it;
       }
       if (it != end && *it != '}') {
         if (*it != ':') report_error("invalid format specifier");
         ++it;
       }
       ctx.advance_to(it);
     }
     detail::for_each(formatters_, detail::parse_empty_specs<Char>{ctx});
     return it;
   }
 
   template <typename FormatContext>
   auto format(map_type& map, FormatContext& ctx) const -> decltype(ctx.out()) {
     auto out = ctx.out();
     basic_string_view<Char> open = detail::string_literal<Char, '{'>{};
     if (!no_delimiters_) out = detail::copy<Char>(open, out);
     int i = 0;
     basic_string_view<Char> sep = detail::string_literal<Char, ',', ' '>{};
     for (auto&& value : map) {
       if (i > 0) out = detail::copy<Char>(sep, out);
       ctx.advance_to(out);
       detail::for_each2(formatters_, value,
                         detail::format_tuple_element<FormatContext>{
                             0, ctx, detail::string_literal<Char, ':', ' '>{}});
       ++i;
     }
     basic_string_view<Char> close = detail::string_literal<Char, '}'>{};
     if (!no_delimiters_) out = detail::copy<Char>(close, out);
     return out;
   }
 };
 
 // A (debug_)string formatter.
 template <typename R, typename Char>
 struct formatter<
     R, Char,
     enable_if_t<range_format_kind<R, Char>::value == range_format::string ||
                 range_format_kind<R, Char>::value ==
                     range_format::debug_string>> {
  private:
   using range_type = detail::maybe_const_range<R>;
   using string_type =
       conditional_t<std::is_constructible<
                         detail::std_string_view<Char>,
                         decltype(detail::range_begin(std::declval<R>())),
                         decltype(detail::range_end(std::declval<R>()))>::value,
                     detail::std_string_view<Char>, std::basic_string<Char>>;
 
   formatter<string_type, Char> underlying_;
 
  public:
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     return underlying_.parse(ctx);
   }
 
   template <typename FormatContext>
   auto format(range_type& range, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     auto out = ctx.out();
     if (detail::const_check(range_format_kind<R, Char>::value ==
                             range_format::debug_string))
       *out++ = '"';
     out = underlying_.format(
         string_type{detail::range_begin(range), detail::range_end(range)}, ctx);
     if (detail::const_check(range_format_kind<R, Char>::value ==
                             range_format::debug_string))
       *out++ = '"';
     return out;
   }
 };
 
 template <typename It, typename Sentinel, typename Char = char>
 struct join_view : detail::view {
   It begin;
   Sentinel end;
   basic_string_view<Char> sep;
 
   join_view(It b, Sentinel e, basic_string_view<Char> s)
       : begin(std::move(b)), end(e), sep(s) {}
 };
 
 template <typename It, typename Sentinel, typename Char>
 struct formatter<join_view<It, Sentinel, Char>, Char> {
  private:
   using value_type =
 #ifdef __cpp_lib_ranges
       std::iter_value_t<It>;
 #else
       typename std::iterator_traits<It>::value_type;
 #endif
   formatter<remove_cvref_t<value_type>, Char> value_formatter_;
 
   using view = conditional_t<std::is_copy_constructible<It>::value,
                              const join_view<It, Sentinel, Char>,
                              join_view<It, Sentinel, Char>>;
 
  public:
   using nonlocking = void;
 
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     return value_formatter_.parse(ctx);
   }
 
   template <typename FormatContext>
   auto format(view& value, FormatContext& ctx) const -> decltype(ctx.out()) {
     using iter =
         conditional_t<std::is_copy_constructible<view>::value, It, It&>;
     iter it = value.begin;
     auto out = ctx.out();
     if (it == value.end) return out;
     out = value_formatter_.format(*it, ctx);
     ++it;
     while (it != value.end) {
       out = detail::copy<Char>(value.sep.begin(), value.sep.end(), out);
       ctx.advance_to(out);
       out = value_formatter_.format(*it, ctx);
       ++it;
     }
     return out;
   }
 };
 
 template <typename Char, typename Tuple> struct tuple_join_view : detail::view {
   const Tuple& tuple;
   basic_string_view<Char> sep;
 
   tuple_join_view(const Tuple& t, basic_string_view<Char> s)
       : tuple(t), sep{s} {}
 };
 
 // Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
 // support in tuple_join. It is disabled by default because of issues with
 // the dynamic width and precision.
 #ifndef FMT_TUPLE_JOIN_SPECIFIERS
 #  define FMT_TUPLE_JOIN_SPECIFIERS 0
 #endif
 
 template <typename Char, typename Tuple>
 struct formatter<tuple_join_view<Char, Tuple>, Char,
                  enable_if_t<is_tuple_like<Tuple>::value>> {
   FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     return do_parse(ctx, std::tuple_size<Tuple>());
   }
 
   template <typename FormatContext>
   auto format(const tuple_join_view<Char, Tuple>& value,
               FormatContext& ctx) const -> typename FormatContext::iterator {
     return do_format(value, ctx, std::tuple_size<Tuple>());
   }
 
  private:
   decltype(detail::tuple::get_formatters<Tuple, Char>(
       detail::tuple_index_sequence<Tuple>())) formatters_;
 
   FMT_CONSTEXPR auto do_parse(parse_context<Char>& ctx,
                               std::integral_constant<size_t, 0>)
       -> const Char* {
     return ctx.begin();
   }
 
   template <size_t N>
   FMT_CONSTEXPR auto do_parse(parse_context<Char>& ctx,
                               std::integral_constant<size_t, N>)
       -> const Char* {
     auto end = ctx.begin();
 #if FMT_TUPLE_JOIN_SPECIFIERS
     end = std::get<std::tuple_size<Tuple>::value - N>(formatters_).parse(ctx);
     if (N > 1) {
       auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
       if (end != end1)
         report_error("incompatible format specs for tuple elements");
     }
 #endif
     return end;
   }
 
   template <typename FormatContext>
   auto do_format(const tuple_join_view<Char, Tuple>&, FormatContext& ctx,
                  std::integral_constant<size_t, 0>) const ->
       typename FormatContext::iterator {
     return ctx.out();
   }
 
   template <typename FormatContext, size_t N>
   auto do_format(const tuple_join_view<Char, Tuple>& value, FormatContext& ctx,
                  std::integral_constant<size_t, N>) const ->
       typename FormatContext::iterator {
     using std::get;
     auto out =
         std::get<std::tuple_size<Tuple>::value - N>(formatters_)
             .format(get<std::tuple_size<Tuple>::value - N>(value.tuple), ctx);
     if (N <= 1) return out;
     out = detail::copy<Char>(value.sep, out);
     ctx.advance_to(out);
     return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
   }
 };
 
 namespace detail {
 // Check if T has an interface like a container adaptor (e.g. std::stack,
 // std::queue, std::priority_queue).
 template <typename T> class is_container_adaptor_like {
   template <typename U> static auto check(U* p) -> typename U::container_type;
   template <typename> static void check(...);
 
  public:
   static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 template <typename Container> struct all {
   const Container& c;
   auto begin() const -> typename Container::const_iterator { return c.begin(); }
   auto end() const -> typename Container::const_iterator { return c.end(); }
 };
 }  // namespace detail
 
 template <typename T, typename Char>
 struct formatter<
     T, Char,
     enable_if_t<conjunction<detail::is_container_adaptor_like<T>,
                             bool_constant<range_format_kind<T, Char>::value ==
                                           range_format::disabled>>::value>>
     : formatter<detail::all<typename T::container_type>, Char> {
   using all = detail::all<typename T::container_type>;
   template <typename FormatContext>
   auto format(const T& value, FormatContext& ctx) const -> decltype(ctx.out()) {
     struct getter : T {
       static auto get(const T& v) -> all {
         return {v.*(&getter::c)};  // Access c through the derived class.
       }
     };
     return formatter<all>::format(getter::get(value), ctx);
   }
 };
 
 FMT_BEGIN_EXPORT
 
 /// Returns a view that formats the iterator range `[begin, end)` with elements
 /// separated by `sep`.
 template <typename It, typename Sentinel>
 auto join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel> {
   return {std::move(begin), end, sep};
 }
 
 /**
  * Returns a view that formats `range` with elements separated by `sep`.
  *
  * **Example**:
  *
  *     auto v = std::vector<int>{1, 2, 3};
  *     fmt::print("{}", fmt::join(v, ", "));
  *     // Output: 1, 2, 3
  *
  * `fmt::join` applies passed format specifiers to the range elements:
  *
  *     fmt::print("{:02}", fmt::join(v, ", "));
  *     // Output: 01, 02, 03
  */
 template <typename Range, FMT_ENABLE_IF(!is_tuple_like<Range>::value)>
 auto join(Range&& r, string_view sep)
     -> join_view<decltype(detail::range_begin(r)),
                  decltype(detail::range_end(r))> {
   return {detail::range_begin(r), detail::range_end(r), sep};
 }
 
 /**
  * Returns an object that formats `std::tuple` with elements separated by `sep`.
  *
  * **Example**:
  *
  *     auto t = std::tuple<int, char>{1, 'a'};
  *     fmt::print("{}", fmt::join(t, ", "));
  *     // Output: 1, a
  */
 template <typename Tuple, FMT_ENABLE_IF(is_tuple_like<Tuple>::value)>
 FMT_CONSTEXPR auto join(const Tuple& tuple, string_view sep)
     -> tuple_join_view<char, Tuple> {
   return {tuple, sep};
 }
 
 /**
  * Returns an object that formats `std::initializer_list` with elements
  * separated by `sep`.
  *
  * **Example**:
  *
  *     fmt::print("{}", fmt::join({1, 2, 3}, ", "));
  *     // Output: "1, 2, 3"
  */
 template <typename T>
 auto join(std::initializer_list<T> list, string_view sep)
     -> join_view<const T*, const T*> {
   return join(std::begin(list), std::end(list), sep);
 }
 
 FMT_END_EXPORT
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

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