Function rustc_session::parse::feature_err

source · 
pub fn feature_err(
    sess: &Session,
    feature: Symbol,
    span: impl Into<MultiSpan>,
    explain: impl Into<DiagMessage>
) -> Diag<'_>
Expand description

Construct a diagnostic for a language feature error due to the given span. The feature’s Symbol is the one you used in unstable.rs and rustc_span::symbols.