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std::basic_format_arg(3)      C++ Standard Libary     std::basic_format_arg(3)

NAME
       std::basic_format_arg - std::basic_format_arg

Synopsis
	  Defined in header <format>
	  template<class Context>     (since C++20)
	  class	basic_format_arg;

	  Provides access to a formatting argument.

	  basic_format_arg  objects  are  typically  created by	std::make_for-
       mat_args	and accessed
	  through std::visit_format_arg.

	  A basic_format_arg object behaves as if it stores a std::variant  of
       the following
	  types:

	    * std::monostate (only if the object was default-constructed)
	    * bool
	    * Context::char_type
	    * int
	    * unsigned int
	    * long long	int
	    * unsigned long long int
	    * float
	    * double
	    * long double
	    * const Context::char_type*
	    * std::basic_string_view<Context::char_type>
	    * const void*
	    * basic_format_arg::handle

Member classes
	  Type	 Definition
	  handle type-erased wrapper that allows formatting an object of user-
       defined type
		 (class)

Member functions
	  constructor	constructs a std::basic_format_arg
			(public	member function)
	  operator  bool checks	if the current object holds a formatting argu-
       ment
			(public	member function)

Non-member functions
	  visit_format_arg argument visitation interface for user-defined for-
       matters
	  (C++20)	   (function template)

       std::basic_format_arg::handle

	  template<class Context>
	  class	basic_format_arg<Context>::handle;

	  Allows formatting an object of a user-defined	type.

Member functions
	  format formats the referenced	object with the	given contexts
		 (public member	function)

       std::basic_format_arg::handle::format

	  void	   format(std::basic_format_parse_context<Context::char_type>&
       parse_ctx,
	  Context& format_ctx) const;

	  Let  T  be  the type of the associated formatting argument, ref be a
       const T&	that
	  refers to the	formatting argument. Equivalent	to:

	  typename Context::template formatter_type<T> f;
	  parse_ctx.advance_to(f.parse(parse_ctx));
	  format_ctx.advance_to(f.format(ref, format_ctx));

       std::basic_format_arg::basic_format_arg

	  basic_format_arg() noexcept;

	  Default constructor. Constructs a  basic_format_arg  that  does  not
       hold a formatting
	  argument. The	stored object has type std::monostate.

	  To  create  a	 basic_format_arg  that	 holds	a formatting argument,
       std::make_format_args
	  has to be used.

       std::basic_format_arg::operator bool

	  explicit operator bool() const noexcept;

	  Checks whether *this holds a formatting argument.

	  Returns true if *this	holds a	formatting argument (i.e.  the	stored
       object does not
	  have type std::monostate), false otherwise.

Example
	   This	section	is incomplete
	   Reason: no example

See also
http://cppreference.com		  2022.07.31	      std::basic_format_arg(3)

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