NAME¶

std::vprint_nonunicode,std::vprint_nonunicode_locking - std::vprint_nonunicode,std::vprint_nonunicode_locking

Synopsis¶

Defined in header <print>
void vprint_nonunicode( std::string_view fmt, std::format_args (1) (since C++23)
args );
void vprint_nonunicode( std::FILE* stream,
std::string_view fmt, std::format_args (2) (since C++23)
args );
void vprint_nonunicode_locking( std::FILE* stream,
std::string_view fmt, (3) (since C++23)
std::format_args args );

Format args according to the format string fmt, and writes the result to the output
stream.

1) Equivalent to std::vprint_nonunicode(stdout, fmt, args).
2) Equivalent to std::string out = std::vformat(fmt, args);
std::vprint_nonunicode_locking(stream, "{}", std::make_format_args(out));.
3) While holding the lock on stream, writes the character representation of
formatting arguments provided by args formatted according to specifications given in
fmt to stream.
If stream is not a valid pointer to an output C stream, the behavior is undefined.

Parameters¶

stream - output file stream to write to

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

specifies the index of the argument in args whose value is to
be used for formatting; if it is omitted, the arguments are
arg-id - used in order.

The arg-id s in a format string must all be present or all be
omitted. Mixing manual and automatic indexing is an error.
fmt - the format specification defined by the std::formatter
format-spec - specialization for the corresponding argument. Cannot start
with }.

* 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 range types, the format specification is interpreted
as range format specification.
* For std::pair and std::tuple, the format specification is
interpreted as tuple format specification.
* For std::thread::id and std::stacktrace_entry, see thread (since C++23)
id format specification and stacktrace entry format
specification.
* For std::basic_stacktrace, no format specifier is
allowed.

* For std::filesystem::path, see path format specification. (since C++26)

* For other formattable types, the format specification is determined by
user-defined formatter specializations.
args - arguments to be formatted

Exceptions¶

* std::bad_alloc on allocation failure.
* std::system_error, if writing to the stream fails.
* Propagates any exception thrown by used formatters, e.g. std::format_error.

Notes¶

Feature-test macro Value Std Feature
202207L (C++23) Formatted output
__cpp_lib_print 202403L (C++26) Formatted output with stream locking
(DR23)
__cpp_lib_format 202207L (C++23) Exposing std::basic_format_string

Example¶

This section is incomplete
Reason: no example

See also¶

vprint_unicode prints to Unicode capable stdout or a file stream
vprint_unicode_locking using type-erased argument representation
(C++23) (function)
(C++23)
vprint_nonunicode(std::ostream) outputs character data using type-erased argument
(C++23) representation
(function)
print prints to stdout or a file stream using formatted
(C++23) representation of the arguments
(function template)
format stores formatted representation of the arguments in
(C++20) a new string
(function template)

Category:¶

* Todo no example