std::vprint...d::ostream)(3)

💖 NAME 💖

std::vprint_nonunicode(std::ostream) — literally std::vprint_nonunicode(std::ostream). That’s the name, bestie. This page lives in the C++ Standard Libary manual, and we’re folding that manual name in right here instead of copying the header line. 💅

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✨ Synopsis ✨

Defined in header <ostream>:

void vprint_nonunicode( std::ostream& os, std::string_view fmt, std::format_args args );

(since C++23)

Behaves as FormattedOutputFunction (except that some details of error reporting differ):

• First, constructs and checks the sentry object.
• Then, initializes an automatic variable as if by std::string out = std::vformat(os.getloc(), fmt, args);.
• Finally, inserts the character sequence [out.begin(), out.end()) into os.

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🎀 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) }
{ arg-id (optional) : format-spec }

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. Cannot start with }.

And for the format spec itself:

• 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. (since C++23)
• For std::thread::id and std::stacktrace_entry, see thread 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.

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🦋 Return value 🦋

(none)

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🔥 Exceptions 🔥

• std::bad_alloc on allocation failure.
• Propagate any exception thrown by any formatter, e.g. std::format_error, without regard to the value of os.exceptions() and without turning on ios_base::badbit in the error state of os.
• May throw ios_base::failure caused by os.setstate(ios_base::badbit) which is called if an insertion into os fails.

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💅 Notes 💅

Feature-test macro tea ☕:

• __cpp_lib_print — value 202207L — Std (C++23) — feature: Formatted output
• __cpp_lib_format — value 202207L — Std (C++23) — feature: Exposing std::basic_format_string

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🌈 Example 🌈

This section is incomplete.

Reason: no example.

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👑 See also 👑

• vprint_unicode(std::ostream) (C++23) — performs Unicode aware output using type-erased argument representation (function)
• print(std::ostream) (C++23) — outputs formatted representation of the arguments (function template)
• operator<<(std::basic_ostream) — inserts character data or insert into rvalue stream (function template)
• vprint_nonunicode (C++23) — prints to stdout or a file stream using type-erased argument representation (function)
• vprint_nonunicode_locking (C++23) — prints to stdout or a file stream using type-erased argument representation (function)
• format (C++20) — stores formatted representation of the arguments in a new string (function template)

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🍓 Category 🍓

• Todo no example

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okay that’s the whole page, bestie. Big love to cppreference.com — page date 2024.06.10 — that’s the footer tea, and we’re done 🫶💖