Function span_lint_and_then

pub fn span_lint_and_then<C, S, M, F>(
    cx: &C,
    lint: &'static Lint,
    sp: S,
    msg: M,
    f: F,
)
where
    C: LintContext,
    S: Into<MultiSpan>,
    M: Into<DiagMessage>,
    F: FnOnce(&mut Diag<'_, ()>),

Like span_lint but allows to add notes, help and suggestions using a closure.

If you need to customize your lint output a lot, use this function. If you change the signature, remember to update the internal lint CollapsibleCalls

NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine the lint level. For the span_lint_and_then function, the node that was passed into the LintPass::check_* function is used.

If you’re emitting the lint at the span of a different node than the one provided by the LintPass::check_* function, consider using span_lint_hir_and_then instead. This is needed for #[allow] and #[expect] attributes to work on the node highlighted in the displayed warning.

If you’re unsure which function you should use, you can test if the #[allow] attribute works where you would expect it to. If it doesn’t, you likely need to use span_lint_hir_and_then instead.