diff options
| -rw-r--r-- | src/test/ui/unboxed-closures/issue-53448.rs | 15 | ||||
| -rw-r--r-- | src/test/ui/unboxed-closures/issue-53448.stderr | 20 |
2 files changed, 35 insertions, 0 deletions
diff --git a/src/test/ui/unboxed-closures/issue-53448.rs b/src/test/ui/unboxed-closures/issue-53448.rs new file mode 100644 index 00000000000..5c82a56e77e --- /dev/null +++ b/src/test/ui/unboxed-closures/issue-53448.rs @@ -0,0 +1,15 @@ +#![feature(unboxed_closures)] + +trait Lt<'a> { + type T; +} +impl<'a> Lt<'a> for () { + type T = (); +} + +fn main() { + let v: <() as Lt<'_>>::T = (); + let f: &mut dyn FnMut<(_,), Output = ()> = &mut |_: <() as Lt<'_>>::T| {}; + //~^ ERROR: the size for values of type `<() as Lt<'_>>::T` cannot be known + f(v); +} diff --git a/src/test/ui/unboxed-closures/issue-53448.stderr b/src/test/ui/unboxed-closures/issue-53448.stderr new file mode 100644 index 00000000000..bece9eedc7f --- /dev/null +++ b/src/test/ui/unboxed-closures/issue-53448.stderr @@ -0,0 +1,20 @@ +error[E0277]: the size for values of type `<() as Lt<'_>>::T` cannot be known at compilation time + --> $DIR/issue-53448.rs:12:54 + | +LL | let f: &mut dyn FnMut<(_,), Output = ()> = &mut |_: <() as Lt<'_>>::T| {}; + | ^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `<() as Lt<'_>>::T` + = help: unsized locals are gated as an unstable feature +help: consider further restricting the associated type + | +LL | fn main() where <() as Lt<'_>>::T: Sized { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +help: function arguments must have a statically known size, borrowed types always have a known size + | +LL | let f: &mut dyn FnMut<(_,), Output = ()> = &mut |_: &<() as Lt<'_>>::T| {}; + | ^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`. |