View source for cpp/io/basic ostream/vprint unicode

{{cpp/title|vprint_unicode{{small|(std::ostream)}}}}
{{cpp/io/basic_ostream/navbar}}
{{dcl begin}}
{{dcl header|ostream}}
{{dcl|since=c++23|1=
void vprint_unicode( std::ostream& os, std::string_view fmt, std::format_args args );
}}
{{dcl end}}

Behaves as {{named req|FormattedOutputFunction}} (except that some details of error reporting [[#Exceptions|differ]]):
* First, the function constructs and checks the {{rlp|sentry}} object.
* Then, initializes an automatic variable as if by {{c|1=std::string out = std::vformat(os.getloc(), fmt, args);}}.
* Finally, inserts the character sequence {{tt|[out.begin(), out.end())}} into {{c|os}}, that is, if {{c|os}} refers to a terminal capable of displaying Unicode, writes {{c|out}} to this terminal using the native Unicode API. Otherwise, writes unmodified {{c|out}} to the {{c|os}}.

===Parameters===
{{par begin}}
{{par|os|output stream to insert data into}}
{{par|fmt|{{include|cpp/utility/format/format string}}}}
{{par|args|arguments to be formatted}}
{{par end}}

===Return value===
(none)

===Exceptions===
{{std print ostream exceptions}}

===Notes===
If invoking the native Unicode API requires transcoding, the invalid code units are substituted with {{tt|U+FFFD}} REPLACEMENT CHARACTER (see "The Unicode Standard Version 14.0 - Core Specification", [[#External links|Chapter 3.9]]).

{{ftm begin|std=1|value=1|comment=1}}
{{ftm|std=C++23|value=202207L|__cpp_lib_print|Formatted output}}
{{ftm|std=C++23|value=202207L|__cpp_lib_format|Exposing {{lc|std::basic_format_string}}}}
{{ftm end}}

===Example===
{{example
|code=
|output=
}}

===See also===
{{dsc begin}}
{{dsc inc|cpp/io/basic_ostream/dsc vprint_nonunicode}}
{{dsc inc|cpp/io/basic_ostream/dsc print}}
{{dsc inc|cpp/io/basic_ostream/dsc operator ltlt2}}
{{dsc inc|cpp/io/dsc vprint_unicode}}
{{dsc inc|cpp/utility/format/dsc format}}
{{dsc end}}

===External links===
{{elink begin}}
{{elink|num=1|{{enwiki|Unicode|Unicode}}}}
{{elink|num=2|[https://www.unicode.org/versions/Unicode14.0.0/UnicodeStandard-14.0.pdf The Unicode Standard Version 14.0 - Core Specification]}}
{{elink end}}

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