Add tests

tests/ui/pattern/usefulness/unions.rs

@@ -0,0 +1,34 @@
+fn main() {
+ #[derive(Copy, Clone)]
+ union U8AsBool {
+ n: u8,
+ b: bool,
+ }
+
+ let x = U8AsBool { n: 1 };
+ unsafe {
+ match x {
+ // exhaustive
+ U8AsBool { n: 2 } => {}
+ U8AsBool { b: true } => {}
+ U8AsBool { b: false } => {}
+ }
+ match x {
+ // exhaustive
+ U8AsBool { b: true } => {}
+ U8AsBool { n: 0 } => {}
+ U8AsBool { n: 1.. } => {}
+ }
+ match x {
+ //~^ ERROR non-exhaustive patterns: `U8AsBool { n: 0_u8, b: false }` not covered
+ U8AsBool { b: true } => {}
+ U8AsBool { n: 1.. } => {}
+ }
+ match (x, true) {
+ //~^ ERROR non-exhaustive patterns: `(U8AsBool { n: 0_u8, b: false }, false)` and `(U8AsBool { n: 0_u8, b: true }, false)` not covered
+ (U8AsBool { b: true }, true) => {}
+ (U8AsBool { b: false }, true) => {}
+ (U8AsBool { n: 1.. }, true) => {}
+ }
+ }
+}

tests/ui/pattern/usefulness/unions.stderr

@@ -0,0 +1,34 @@
+error[E0004]: non-exhaustive patterns: `U8AsBool { n: 0_u8, b: false }` not covered
+ --> $DIR/unions.rs:22:15
+ |
+LL | match x {
+ | ^ pattern `U8AsBool { n: 0_u8, b: false }` not covered
+ |
+note: `U8AsBool` defined here
+ --> $DIR/unions.rs:3:11
+ |
+LL | union U8AsBool {
+ | ^^^^^^^^
+ = note: the matched value is of type `U8AsBool`
+help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
+ |
+LL ~ U8AsBool { n: 1.. } => {},
+LL + U8AsBool { n: 0_u8, b: false } => todo!()
+ |
+
+error[E0004]: non-exhaustive patterns: `(U8AsBool { n: 0_u8, b: false }, false)` and `(U8AsBool { n: 0_u8, b: true }, false)` not covered
+ --> $DIR/unions.rs:27:15
+ |
+LL | match (x, true) {
+ | ^^^^^^^^^ patterns `(U8AsBool { n: 0_u8, b: false }, false)` and `(U8AsBool { n: 0_u8, b: true }, false)` not covered
+ |
+ = note: the matched value is of type `(U8AsBool, bool)`
+help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern, a match arm with multiple or-patterns as shown, or multiple match arms
+ |
+LL ~ (U8AsBool { n: 1.. }, true) => {},
+LL + (U8AsBool { n: 0_u8, b: false }, false) | (U8AsBool { n: 0_u8, b: true }, false) => todo!()
+ |
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0004`.