Contains the implementation details of the implementation-defined behavior in libc++. Implementation-defined is mandated to be documented by the Standard.
Updating the Time Zone Database¶
The Standard allows implementations to automatically update the remote time zone database. Libc++ opts not to do that. Instead calling
std::chrono::remote_version()will update the version information of the remote time zone database,
std::chrono::reload_tzdb(), if needed, will update the entire remote time zone database.
This offers a way for users to update the remote time zone database and give them full control over the process.
[ostream.formatted.print]/3 A terminal capable of displaying Unicode¶
The Standard specifies that the manner in which a stream is determined to refer
to a terminal capable of displaying Unicode is implementation-defined. This is
std::print and similar functions taking an
Libc++ determines that a stream is Unicode-capable terminal by:
First it determines whether the stream’s
rdbuf()has an underlying
FILE*. This is
truein the following cases:
The stream is
std::basic_filebuf<CharT, Traits>derived from
The way to determine whether this
FILE*refers to a terminal capable of displaying Unicode is the same as specified for void vprint_unicode(FILE* stream, string_view fmt, format_args args);. This function is used for other
std::printoverloads that don’t take an
Listed in the index of implementation-defined behavior¶
The order of the entries matches the entries in the draft of the Standard.