fmt::formatter

Synopsis

Declared in <fmt/base.h>

template<
    typename T,
    typename Char = char,
    typename Enable = void>
struct formatter;

Member Functions

Name	Description
`formatter` [constructor] [deleted]	Deleted to indicate that this formatter is disabled by default; a specialization must define a usable default constructor to enable formatting for a given `T`.

Specializations

Name	Description
`formatter</* implementation-defined */>`	A `formatter` specialization for `detail::bigint`, used to print its value as hexadecimal bigits for debugging.
`formatter<bytes>`	Formats a `bytes` view using the string presentation rules.
`formatter<std::error_code>`	Formats `std::error_code` as `category:value`, or as its `message()` when the `s` type specifier is given.
`formatter<__exception_ptr::exception_ptr>`	Formats `std::exception_ptr` by rethrowing and formatting the exception it holds, or as `none` when empty.
`formatter<std::source_location>`	Formats `std::source_location` as `file:line:column: function`.
`formatter<std::type_info>`	Formats `std::type_info` as its demangled type name.
`formatter<group_digits_view<T>>`	Formats a `group_digits_view` by writing its integer value with ',' as a thousands separator.
`formatter<T, char>`	Formats any type derived from `std::exception` as its `what()` message, optionally prefixed with its demangled type name when the `t` specifier is given.
`formatter<std::atomic_flag, Char>`	Formats `std::atomic_flag` the same way as the `bool` returned by `test`.
`formatter<std::byte, Char>`	Formats `std::byte` the same way as the `unsigned char` it holds.
`formatter<day, Char>`	Formats a `fmt::day`.
`formatter</* implementation-defined */, Char>`	Specializes `formatter` for `detail::float128`, an extended-precision floating-point type, reusing the native floating-point formatting logic.
`formatter<std::thread::id, Char>`	Formats `std::thread::id` the same way as its `operator<<` overload, via `basic_ostream_formatter`.
`formatter<long, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<std::monostate, Char>`	Formats `std::monostate` as the literal string `monostate`.
`formatter<month, Char>`	Formats a `fmt::month`.
`formatter<std::nullptr_t, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<std::filesystem::path, Char>`	Formats `std::filesystem::path`, honoring the `?` debug-quoting and `g` generic-path-format specifiers.
`formatter<short, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<signed char, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<tm, Char>`	Formats a `std::tm`.
`formatter<unsigned char, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<unsigned long, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<unsigned short, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<weekday, Char>`	Formats a `fmt::weekday`.
`formatter<year, Char>`	Formats a `fmt::year`.
`formatter<year_month_day, Char>`	Formats a `fmt::year_month_day`.
`formatter</* implementation-defined */, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<Char*, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<void*, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<BitRef, Char>`	Formats a bit-reference proxy (e.g. `std::vector<bool>::reference` or `std::bitset<N>::reference`) the same way as the `bool` it refers to.
`formatter<R, Char>`	Formats a range `R` as a bracketed, separator-delimited sequence of its elements, for range kinds other than map, string, and debug string.
`formatter<R, Char>`	Formats a map-like range `R` as a `{key: value, ...}` sequence of its key-value pairs.
`formatter<R, Char>`	Formats a range `R` of characters as a string, quoting and escaping it when `R`'s range format kind is `debug_string`.
`formatter<T, Char>`	A formatter specialization for natively supported types.
`formatter<T, Char>`	Formats a container adaptor `T` (like `std::stack`) as its underlying container.
`formatter<Tuple, Char>`	Formats a tuple-like type as a parenthesized, separator-delimited sequence of its elements.
`formatter<Variant, Char>`	Formats a variant-like type as `variant(alternative)`, or as `valueless by exception` if it holds no value.
`formatter<std::atomic<T>, Char>`	Formats `std::atomic<T>` the same way as the `T` value it holds, loading it before formatting.
`formatter<std::bitset<N>, Char>`	Formats `std::bitset<N>` as a string of `'0'`/`'1'` characters, most significant bit first.
`formatter<std::complex<T>, Char>`	Formats `std::complex<T>` as `real+imagi` (or `real-imagi`), applying the parsed specs to both the real and imaginary parts.
`formatter<local_time<Duration>, Char>`	Formats a `std::chrono::local_time`, which has an unspecified time zone.
`formatter<nested_view<T, Char>, Char>`	Formats a `nested_view` by delegating to its stored formatter.
`formatter<std::optional<T>, Char>`	Formats `std::optional<T>` as `optional(value)`, or as `none` when it is empty.
`formatter<std::reference_wrapper<T>, Char>`	Formats `std::reference_wrapper<T>` the same way as the referenced `T`.
`formatter</* implementation-defined */, Char>`	A formatter for values wrapped with `fmt::streamed`, which formats the wrapped value via its ostream `operator<<`.
`formatter</* implementation-defined */, Char>`	Formatter for a value wrapped by `fmt::styled`, applying the wrapped text style around the underlying formatter's output.
`formatter<sys_time<Duration>, Char>`	Formats a `std::chrono::sys_time`.
`formatter<tuple_join_view<Tuple, Char>, Char>`	Formats a `tuple_join_view`, writing each tuple element with its own formatter, separated by `tuple_join_view::sep`.
`formatter</* implementation-defined */, Char>`	Formats a signed bit-precise integer (`_BitInt(N)`) the same way as `long long`, by first converting it.
`formatter<std::unexpected<E>, Char>`	Formats `std::unexpected<E>` as `unexpected(error)`.
`formatter<utc_time<Duration>, Char>`	Formats a `std::chrono::utc_time`.
`formatter<Char[], Char>`	Specializes `formatter` for character arrays (string literals), formatting them as `basic_string_view<Char>`.
`formatter<std::basic_string<Char, Traits, Allocator>, Char>`	Specializes `formatter` for `std::basic_string`, formatting it as `basic_string_view<Char>`.
`formatter<std::chrono::duration<Rep, Period>, Char>`	Formats a `std::chrono::duration`.
`formatter<std::expected<T, E>, Char>`	Formats `std::expected<T, E>` as `expected(value)` when it holds a value, or as `unexpected(error)` when it holds an error.
`formatter<join_view<It, Sentinel, Char>, Char>`	Formats a `join_view`, writing each element with its own formatter, separated by `join_view::sep`.
`formatter<T, Char, void_t</* implementation-defined */>>`	Specializes `formatter` for types `T` that have an associated `format_as` overload, by formatting the result of `format_as(value)` instead of `T` directly.

Derived Classes

Name	Description
`basic_ostream_formatter`	Formats an object of type T that has an overloaded ostream operator<<.
`formatter<void*, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<long, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<unsigned short, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<std::reference_wrapper<T>, Char>`	Formats `std::reference_wrapper<T>` the same way as the referenced `T`.
`formatter<short, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<T, Char>`	Formats a container adaptor `T` (like `std::stack`) as its underlying container.
`formatter<group_digits_view<T>>`	Formats a `group_digits_view` by writing its integer value with ',' as a thousands separator.
`formatter<std::byte, Char>`	Formats `std::byte` the same way as the `unsigned char` it holds.
`formatter<T, Char, void_t</* implementation-defined */>>`	Specializes `formatter` for types `T` that have an associated `format_as` overload, by formatting the result of `format_as(value)` instead of `T` directly.
`formatter<Char[], Char>`	Specializes `formatter` for character arrays (string literals), formatting them as `basic_string_view<Char>`.
`formatter<std::basic_string<Char, Traits, Allocator>, Char>`	Specializes `formatter` for `std::basic_string`, formatting it as `basic_string_view<Char>`.
`formatter<BitRef, Char>`	Formats a bit-reference proxy (e.g. `std::vector<bool>::reference` or `std::bitset<N>::reference`) the same way as the `bool` it refers to.
`formatter<std::atomic_flag, Char>`	Formats `std::atomic_flag` the same way as the `bool` returned by `test`.
`formatter</* implementation-defined */, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<unsigned char, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter</* implementation-defined */, Char>`	Formats a signed bit-precise integer (`_BitInt(N)`) the same way as `long long`, by first converting it.
`formatter<std::nullptr_t, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter</* implementation-defined */, Char>`	Formatter for a value wrapped by `fmt::styled`, applying the wrapped text style around the underlying formatter's output.
`formatter<utc_time<Duration>, Char>`	Formats a `std::chrono::utc_time`.
`formatter<signed char, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<unsigned long, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<__exception_ptr::exception_ptr>`	Formats `std::exception_ptr` by rethrowing and formatting the exception it holds, or as `none` when empty.
`formatter<Char*, Char>`	Specializes `formatter<Type, Char>` to format `Type` values the same way as `Base`, by delegating to `formatter<Base, Char>`.
`formatter<std::atomic<T>, Char>`	Formats `std::atomic<T>` the same way as the `T` value it holds, loading it before formatting.