std::range-default-formatter<std::range_format::map>

Defined in header `<format>`
`template< ranges::input_range R, class CharT > struct range-default-formatter<range_format::map, R, CharT>;`		(since C++23) (exposition only*)

The class template range-default-formatter for range types is specialized for formatting range as a map of keys to values if std::format_kind<R> is std::range_format::map.

Member types

Member type	Definition
`maybe-const-map` (private)	/fmt-maybe-const/<R, CharT> (exposition-only member type*)
`element-type` (private)	`std::remove_cvref_t<ranges::range_reference_t<maybe-const-map>>`

Member objects

Member name	Definition
`underlying_` (private)	the underlying formatter of type `std::range_formatter<element-type, CharT>` (exposition-only member object*)

Member functions

(constructor)	constructs a `range-default-formatter` (public member function)
parse	parses the format specifier as specified by range-format-spec (public member function)
format	writes the range formatted output as specified by range-format-spec (public member function)

std::range-default-formatter<std::range_format::map>::range-default-formatter

constexpr range-default-formatter();

Equivalent to: underlying_.set_brackets(STATICALLY_WIDEN<CharT>("{"), STATICALLY_WIDEN<CharT>("}"));underlying_.underlying().set_brackets({}, {});underlying_.underlying().set_separator(STATICALLY-WIDEN<charT>(": "));

where STATICALLY_WIDEN<CharT>("...") is "..." if CharT is char, and L"..." if CharT is wchar_t.

The program is ill-formed unless:

element-type is a specialization of std::pair, or
element-type is a specialization of std::tuple and std::tuple_size_v<element-type> is 2.

std::range-default-formatter<std::range_format::map>::parse

template< class ParseContext >
constexpr auto parse( ParseContext& ctx ) -> typename ParseContext::iterator;

Equivalent to return underlying_.parse(ctx);.

Returns an iterator past the end of the range-format-spec.

std::range-default-formatter<std::range_format::map>::format

template< class FormatContext >
auto format( maybe-const-map& r, FormatContext& ctx ) const
    -> typename FormatContext::iterator;

Equivalent to return underlying_.format(r, ctx);.

Returns an iterator past the end of the output range.

formatter (C++20)	defines formatting rules for a given type (class template)
range_formatter (C++23)	class template that helps implementing `std::formatter` specializations for range types (class template)

Docs

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