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

 

C++

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 control library(C++26)

Technical specifications

Symbols index

External libraries

 

Text processing library

Localization library

Regular expressions library(C++11)

Formatting library(C++20)

Null-terminated sequence utilities

Byte strings

Multibyte strings

Wide strings

Primitive numeric conversions

to_chars (C++17) to_chars_result (C++17) from_chars (C++17) from_chars_result (C++17) chars_format (C++17)

Text encoding identifications

text_encoding (C++26)

 

Formatting library

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)

 

std::formatter<range>

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>

 

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 > constexprauto 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.

See also

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)