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Showing content from https://en.cppreference.com/w/cpp/language/../error/error_code/../../../cpp/io/print.html below:

std::print - cppreference.com

(1) (since C++23) (2) (since C++23)

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

1)

Equivalent to

std::print(stdout, fmt, std::forward<Args>(args)...)

If std::formatter<Ti, char> does not meet the BasicFormatter requirements for any Ti in Args (as required by std::make_format_args), the behavior is undefined.

[edit] Parameters stream - output file stream to write to 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-id s 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. 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 other formattable types, the format specification is determined by user-defined formatter specializations.

args... - arguments to be formatted [edit] 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.

[edit] Notes [edit] Example

#include <cstdio>
#include <filesystem>
#include <print>
 
int main()
{
    std::print("{2} {1}{0}!\n", 23, "C++", "Hello");  // overload (1)
 
    const auto tmp{std::filesystem::temp_directory_path() / "test.txt"};
    if (std::FILE* stream{std::fopen(tmp.c_str(), "w")})
    {
        std::print(stream, "File: {}", tmp.string()); // overload (2)
        std::fclose(stream);
    }
}

Output:

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior P3107R5 C++23 only buffered printing operations can be performed can perform unbuffered printing operations P3235R3 C++23 the names of the functions added
by P3107R5 were misleading changed the function names [edit] See also same as std::print except that each print is terminated by additional new line
(function template) [edit] outputs formatted representation of the arguments
(function template) [edit] stores formatted representation of the arguments in a new string
(function template) [edit] writes out formatted representation of its arguments through an output iterator
(function template) [edit] prints formatted output to stdout, a file stream or a buffer
(function) [edit]

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