utility_module::enum_formatter< T, Converter > Class Template Reference

A generic formatter for enum types, using a user-provided converter functor. More...

#include <formatter.h>

Collaboration diagram for utility_module::enum_formatter< T, Converter >:

Public Member Functions
template<typename ParseContext >
constexpr auto	parse (ParseContext &context)
	A no-op parse function required by the formatting library.
template<typename FormatContext >
auto	format (const T &value, FormatContext &context) const
	Formats the enum value into a provided format context.

Static Private Member Functions
template<typename CharT , typename OutputIt >
static auto	do_format (OutputIt &out, const T &value)
	Internal helper that dispatches to std::format based on character type.

Detailed Description

template<typename T, typename Converter>
class utility_module::enum_formatter< T, Converter >

A generic formatter for enum types, using a user-provided converter functor.

The enum_formatter template allows formatting an enum value by converting it to a string (via a custom Converter functor) and then passing that string to C++20's std::format.

Template Parameters

T	The enum type to be formatted.
Converter	A callable object (e.g., a functor or lambda) that accepts an enum value of type T and returns its string representation.

Example

// 1) Define an enum and a corresponding converter functor:
enum class color { Red, Green, Blue };
 
struct color_converter {
    std::string operator()(color c) const {
        switch (c) {
        case color::Red:   return "Red";
        case color::Green: return "Green";
        case color::Blue:  return "Blue";
        }
        return "Unknown";
    }
};
 
// 2) Use enum_formatter<Color, color_converter> to format:
// e.g. std::format("Color: {}", color::Green) // -> "Color: Green"

Definition at line 46 of file formatter.h.

Member Function Documentation

do_format()

template<typename T , typename Converter >

template<typename CharT , typename OutputIt >

static auto utility_module::enum_formatter< T, Converter >::do_format ( OutputIt & out, const T & value )

inlinestaticprivate

Internal helper that dispatches to std::format based on character type.

Template Parameters

CharT	The character type (char or wchar_t).
OutputIt	The output iterator type.

Parameters

out	An output iterator to which formatted text is appended.
value	The enum value to be converted to string and then formatted.

Returns

An iterator pointing to the end of the inserted sequence.

Definition at line 57 of file formatter.h.

        {
            if constexpr (std::is_same_v<CharT, wchar_t>)
            {
                return std::format_to(out, L"{}", Converter{}(value));
            }
            else
            {
                return std::format_to(out, "{}", Converter{}(value));
            }
        }

format()

template<typename T , typename Converter >

template<typename FormatContext >

auto utility_module::enum_formatter< T, Converter >::format ( const T & value, FormatContext & context ) const

inline

Formats the enum value into a provided format context.

Template Parameters

FormatContext

The type of the format context (provided by std::format).

Parameters

value	The enum value to format.
context	The format context, which holds the output iterator and additional state.

Returns

An iterator pointing to the end of the formatted output.

Internally calls the helper do_format() to convert the enum to a string using Converter and then writes it.

Definition at line 92 of file formatter.h.

        {
            using char_type =
                typename std::iterator_traits<typename FormatContext::iterator>::value_type;
            return do_format<char_type>(context.out(), value);
        }

References kcenon::thread::utils::enum_formatter< T, Converter >::do_format().

Here is the call graph for this function:

parse()

template<typename T , typename Converter >

template<typename ParseContext >

auto utility_module::enum_formatter< T, Converter >::parse ( ParseContext & context )

inlineconstexpr

A no-op parse function required by the formatting library.

Template Parameters

ParseContext

The parse context type.

Parameters

context

The format parse context.

Returns

An iterator pointing to the end of context.

The formatter does not accept any custom formatting specifiers, so it simply returns context.begin().

Definition at line 80 of file formatter.h.

{ return context.begin(); }

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The documentation for this class was generated from the following file:

• utilities/include/formatter.h