From 7f5548fa8b22bccdadb3cbe7cf4d566a970eeb25 Mon Sep 17 00:00:00 2001 From: Esteban Küber Date: Sun, 6 Oct 2024 01:44:59 +0000 Subject: On function and method calls in patterns, link to the book ``` error: expected a pattern, found an expression --> f889.rs:3:13 | 3 | let (x, y.drop()) = (1, 2); //~ ERROR | ^^^^^^^^ not a pattern | = note: arbitrary expressions are not allowed in patterns: error[E0532]: expected a pattern, found a function call --> f889.rs:2:13 | 2 | let (x, drop(y)) = (1, 2); //~ ERROR | ^^^^ not a tuple struct or tuple variant | = note: function calls are not allowed in patterns: ``` Fix #97200. --- compiler/rustc_resolve/src/late/diagnostics.rs | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'compiler/rustc_resolve') diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index 35d166e8b4a..fce5ec36c66 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -443,6 +443,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { self.suggest_bare_struct_literal(&mut err); self.suggest_changing_type_to_const_param(&mut err, res, source, span); + self.explain_functions_in_pattern(&mut err, res, source); if self.suggest_pattern_match_with_let(&mut err, source, span) { // Fallback label. @@ -1166,6 +1167,18 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { } } + fn explain_functions_in_pattern( + &mut self, + err: &mut Diag<'_>, + res: Option, + source: PathSource<'_>, + ) { + let PathSource::TupleStruct(_, _) = source else { return }; + let Some(Res::Def(DefKind::Fn, _)) = res else { return }; + err.primary_message("expected a pattern, found a function call"); + err.note("function calls are not allowed in patterns: "); + } + fn suggest_changing_type_to_const_param( &mut self, err: &mut Diag<'_>, -- cgit 1.4.1-3-g733a5