< cpp‎ | utility‎ | format
Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
Three-way comparison
General utilities
Date and time
Function objects
Formatting library (C++20)
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types
Elementary string conversions

Defined in header <format>
template< class Visitor, class Context >
/* see below */ visit_format_arg( Visitor&& vis, std::basic_format_arg<Context> arg );
(since C++20)
(deprecated in C++26)

Applies the visitor vis to the object contained in arg.

Equivalent to std::visit(std::forward<Visitor>(vis), value), where value is the std::variant stored in arg.


[edit] Parameters

vis - a Callable that accepts every possible alternative from arg
arg - a std::basic_format_arg to be visited

[edit] Return value

The value returned by the selected invocation of the visitor.

[edit] Notes

As of C++26, std::visit_format_arg is deprecated in favor of the visit member functions of std::basic_format_arg.

[edit] Example

[edit] See also

creates a type-erased object referencing all formatting arguments, convertible to format_args
(function template) [edit]