pub fn std_source(name: &str) -> Option<&'static str>Expand description
The text of the std module a program’s FileDb names name, such as
<std/time>, or None for any other name. The build adds std’s modules
to the database only after loading, so a MapDiagnostic that shows a
diagnostic in one, as a std doc test’s does (spec 3.5b §7), reads its
text here.