Macro format_err

macro_rules! format_err {
    ($spanned:expr, $($msg:tt)*) => { ... };
}

Creates a syn::Error with the format message and infers the Span using Spanned.

Parameters

• The first argument must be a type that implements syn::spanned::Spanned.
• The second argument is a format string.
• The rest are format string arguments.

Note

On stable Rust this might yield worse error span information to the user than format_err_spanned.

• Source: syn::Error::new_spanned
• Tracking issue: #54725