diff options
Diffstat (limited to 'tests/ui/unboxed-closures/unboxed-closures-counter-not-moved.rs')
-rw-r--r-- | tests/ui/unboxed-closures/unboxed-closures-counter-not-moved.rs | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/tests/ui/unboxed-closures/unboxed-closures-counter-not-moved.rs b/tests/ui/unboxed-closures/unboxed-closures-counter-not-moved.rs new file mode 100644 index 000000000..390386e57 --- /dev/null +++ b/tests/ui/unboxed-closures/unboxed-closures-counter-not-moved.rs @@ -0,0 +1,28 @@ +// run-pass +// Test that we mutate a counter on the stack only when we expect to. + +fn call<F>(f: F) where F : FnOnce() { + f(); +} + +fn main() { + let y = vec![format!("Hello"), format!("World")]; + let mut counter = 22_u32; + + call(|| { + // Move `y`, but do not move `counter`, even though it is read + // by value (note that it is also mutated). + for item in y { //~ WARN unused variable: `item` + let v = counter; + counter += v; + } + }); + assert_eq!(counter, 88); + + call(move || { + // this mutates a moved copy, and hence doesn't affect original + counter += 1; //~ WARN value assigned to `counter` is never read + //~| WARN unused variable: `counter` + }); + assert_eq!(counter, 88); +} |