From 64d98f8ee037282c35007b64c2649055c56af1db Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:03 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- ...issue-67037-pat-tup-scrut-ty-diff-less-fields.rs | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 tests/ui/pattern/issue-67037-pat-tup-scrut-ty-diff-less-fields.rs (limited to 'tests/ui/pattern/issue-67037-pat-tup-scrut-ty-diff-less-fields.rs') diff --git a/tests/ui/pattern/issue-67037-pat-tup-scrut-ty-diff-less-fields.rs b/tests/ui/pattern/issue-67037-pat-tup-scrut-ty-diff-less-fields.rs new file mode 100644 index 000000000..ae28c1403 --- /dev/null +++ b/tests/ui/pattern/issue-67037-pat-tup-scrut-ty-diff-less-fields.rs @@ -0,0 +1,21 @@ +// Regression test for #67037. +// +// In type checking patterns, E0023 occurs when the tuple pattern and the expected +// tuple pattern have different number of fields. For example, as below, `P()`, +// the tuple struct pattern, has 0 fields, but requires 1 field. +// +// In emitting E0023, we try to see if this is a case of e.g., `Some(a, b, c)` but where +// the scrutinee was of type `Some((a, b, c))`, and suggest that parentheses be added. +// +// However, we did not account for the expected type being different than the tuple pattern type. +// This caused an issue when the tuple pattern type (`P`) was generic. +// Specifically, we tried deriving the 0th field's type using the `substs` of the expected type. +// When attempting to substitute `T`, there was no such substitution, so "out of range" occurred. + +struct U {} // 0 type parameters offered +struct P(T); // 1 type parameter wanted + +fn main() { + let P() = U {}; //~ ERROR mismatched types + //~^ ERROR this pattern has 0 fields, but the corresponding tuple struct has 1 field +} -- cgit v1.2.3