22 General utilities library [utilities]

22.14 Formatting [format]

22.14.1 Header <format> synopsis [format.syn]

namespace std { // [format.context], class template basic_­format_­context template<class Out, class charT> class basic_format_context; using format_context = basic_format_context<unspecified, char>; using wformat_context = basic_format_context<unspecified, wchar_t>; // [format.args], class template basic_­format_­args template<class Context> class basic_format_args; using format_args = basic_format_args<format_context>; using wformat_args = basic_format_args<wformat_context>; // [format.fmt.string], class template basic_­format_­string template<class charT, class... Args> struct basic_format_string; template<class... Args> using format_string = basic_format_string<char, type_identity_t<Args>...>; template<class... Args> using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>; // [format.functions], formatting functions template<class... Args> string format(format_string<Args...> fmt, Args&&... args); template<class... Args> wstring format(wformat_string<Args...> fmt, Args&&... args); template<class... Args> string format(const locale& loc, format_string<Args...> fmt, Args&&... args); template<class... Args> wstring format(const locale& loc, wformat_string<Args...> fmt, Args&&... args); string vformat(string_view fmt, format_args args); wstring vformat(wstring_view fmt, wformat_args args); string vformat(const locale& loc, string_view fmt, format_args args); wstring vformat(const locale& loc, wstring_view fmt, wformat_args args); template<class Out, class... Args> Out format_to(Out out, format_string<Args...> fmt, Args&&... args); template<class Out, class... Args> Out format_to(Out out, wformat_string<Args...> fmt, Args&&... args); template<class Out, class... Args> Out format_to(Out out, const locale& loc, format_string<Args...> fmt, Args&&... args); template<class Out, class... Args> Out format_to(Out out, const locale& loc, wformat_string<Args...> fmt, Args&&... args); template<class Out> Out vformat_to(Out out, string_view fmt, format_args args); template<class Out> Out vformat_to(Out out, wstring_view fmt, wformat_args args); template<class Out> Out vformat_to(Out out, const locale& loc, string_view fmt, format_args args); template<class Out> Out vformat_to(Out out, const locale& loc, wstring_view fmt, wformat_args args); template<class Out> struct format_to_n_result { Out out; iter_difference_t<Out> size; }; template<class Out, class... Args> format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, format_string<Args...> fmt, Args&&... args); template<class Out, class... Args> format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, wformat_string<Args...> fmt, Args&&... args); template<class Out, class... Args> format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, const locale& loc, format_string<Args...> fmt, Args&&... args); template<class Out, class... Args> format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n, const locale& loc, wformat_string<Args...> fmt, Args&&... args); template<class... Args> size_t formatted_size(format_string<Args...> fmt, Args&&... args); template<class... Args> size_t formatted_size(wformat_string<Args...> fmt, Args&&... args); template<class... Args> size_t formatted_size(const locale& loc, format_string<Args...> fmt, Args&&... args); template<class... Args> size_t formatted_size(const locale& loc, wformat_string<Args...> fmt, Args&&... args); // [format.formatter], formatter template<class T, class charT = char> struct formatter; // [format.formattable], concept formattable template<class T, class charT> concept formattable = see below; template<class R, class charT> concept const-formattable-range = // exposition only ranges::input_­range<const R> && formattable<ranges::range_reference_t<const R>, charT>; template<class R, class charT> using fmt-maybe-const = // exposition only conditional_t<const-formattable-range<R, charT>, const R, R>; // [format.parse.ctx], class template basic_­format_­parse_­context template<class charT> class basic_format_parse_context; using format_parse_context = basic_format_parse_context<char>; using wformat_parse_context = basic_format_parse_context<wchar_t>; // [format.range], formatting of ranges // [format.range.fmtkind], variable template format_­kind enum class range_format { disabled, map, set, sequence, string, debug_string }; template<class R> constexpr unspecified format_kind = unspecified; template<ranges::input_­range R> requires same_­as<R, remove_cvref_t<R>> constexpr range_format format_kind<R> = see below; // [format.range.formatter], class template range_­formatter template<class T, class charT = char> requires same_­as<remove_cvref_t<T>, T> && formattable<T, charT> class range_formatter; // [format.range.fmtdef], class template range-default-formatter template<range_format K, ranges::input_­range R, class charT> struct range-default-formatter; // exposition only // [format.range.fmtmap], [format.range.fmtset], [format.range.fmtstr], specializations for maps, sets, and strings template<ranges::input_­range R, class charT> requires (format_kind<R> != range_format::disabled) && formattable<ranges::range_reference_t<R>, charT> struct formatter<R, charT> : range-default-formatter<format_kind<R>, R, charT> { }; // [format.arguments], arguments // [format.arg], class template basic_­format_­arg template<class Context> class basic_format_arg; template<class Visitor, class Context> decltype(auto) visit_format_arg(Visitor&& vis, basic_format_arg<Context> arg); // [format.arg.store], class template format-arg-store template<class Context, class... Args> class format-arg-store; // exposition only template<class Context = format_context, class... Args> format-arg-store<Context, Args...> make_format_args(Args&&... fmt_args); template<class... Args> format-arg-store<wformat_context, Args...> make_wformat_args(Args&&... args); // [format.error], class format_­error class format_error; }
The class template format_­to_­n_­result has the template parameters, data members, and special members specified above.
It has no base classes or members other than those specified.