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print(std::basic_ostream)

Defined in header `<ostream>`
template< class... Args > void print( std::ostream& os, std::format_string<Args...> fmt, Args&&... args );		(since C++23)

Formats args according to the format string fmt, and inserts the result into os stream.

If ordinary literal encoding of fmt or any parameter in args... is UTF-8 (where applicable), equivalent to:

std::vprint_unicode(os, fmt.get(), std::make_format_args(std::forward<Args>(args)...));

Otherwise, equivalent to:

std::vprint_nonunicode(os, fmt.get(), std::make_format_args(std::forward<Args>(args)...));

The behavior is undefined if std::formatter<Ti, char> does not model std::formattable for any Ti in Args (as required by std::make_format_args).

Parameters

os - output stream to insert data into

fmt

an object that represents the format string. The format string consists of

ordinary characters (except { and }), which are copied unchanged to the output,
escape sequences {{ and }}, which are replaced with { and } respectively in the output, and
replacement fields.

Each replacement field has the following format:

`{` arg-id (optional) `}`	(1)
`{` arg-id (optional) `:` format-spec `}`	(2)

1) replacement field without a format specification 2) replacement field with a format specification

arg-id	-	specifies the index of the argument in `args` whose value is to be used for formatting; if it is omitted, the arguments are used in order. The arg-ids in a format string must all be present or all be omitted. Mixing manual and automatic indexing is an error.
format-spec	-	the format specification defined by the `std::formatter` specialization for the corresponding argument.

For basic types and standard string types, the format specification is interpreted as standard format specification.
For chrono types, the format specification is interpreted as chrono format specification.
For other formattable types, the format specification is determined by user-defined formatter specializations.

args... - arguments to be formatted

Return value

(none).

Exceptions

Notes

Feature-test macro	Value	Std
`__cpp_lib_print`	`202207L`	(C++23)
`__cpp_lib_format`	`202207L`	(C++23)

println (C++23)	outputs formatted representation of the arguments with appended `'\n'` (function template)
print (C++23)	prints to `stdout` or a file stream using formatted representation of the arguments (function template)
format (C++20)	stores formatted representation of the arguments in a new string (function template)