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	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` >> (exposition-only member type*

Data members

Member	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 ) - > ParseContext:: iterator ;

Equivalent to: return underlying_ .format(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 - > FormatContext:: iterator ;

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

Returns an iterator past the end of the output range.

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Diagnostics library
Memory management library
Metaprogramming library (C++11)
General utilities library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library (C++17)
Concurrency support library (C++11)
Execution support library (C++26)
Technical specifications
Symbols index
External libraries

Standard format specification
Formatting functions
format (C++20)
format_to (C++20)
format_to_n (C++20)
formatted_size (C++20)
vformat (C++20)
vformat_to (C++20)
Format strings
basic_format_stringformat_stringwformat_string (C++20)(C++20)(C++20)
runtime_format (C++26)
Formatting concepts
formattable (C++23)
Formatter
formatter (C++20)
formatter<pair-or-tuple> (C++23)
formatter<range> (C++23)
range_formatter (C++23)
enable_nonlocking_formatter_optimization (C++23)
basic_format_parse_contextformat_parse_contextwformat_parse_context (C++20)(C++20)(C++20)
basic_format_contextformat_contextwformat_context (C++20)(C++20)(C++20)
range_format (C++23)
format_kind (C++23)
Formatting arguments
basic_format_arg (C++20)
basic_format_arg::handle (C++20)
basic_format_argsformat_argswformat_args (C++20)(C++20)(C++20)
visit_format_arg (C++20) (deprecated in C++26)
make_format_argsmake_wformat_args (C++20)(C++20)
Format error
format_error (C++20)

range-default-formatter specializations
range-default-formatter<std::range_format::sequence>
range-default-formatter<std::range_format::map>
range-default-formatter<std::range_format::set>
range-default-formatter<std::range_format::string> range-default-formatter<std::range_format::debug_string>

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)