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|
fn foo(x: u32) -> u32 {
x * 2
}
fn bar(x: u32) -> u32 {
x * 3
}
// original example from Issue #102608
fn foobar(n: u32) -> u32 {
let g = if n % 2 == 0 { &foo } else { &bar };
//~^ ERROR `if` and `else` have incompatible types
//~| different fn items have unique types, even if their signatures are the same
g(n)
}
fn main() {
assert_eq!(foobar(7), 21);
assert_eq!(foobar(8), 16);
// general mismatch of fn item types
let mut a = foo;
a = bar;
//~^ ERROR mismatched types
//~| expected fn item `fn(_) -> _ {foo}`
//~| found fn item `fn(_) -> _ {bar}`
//~| different fn items have unique types, even if their signatures are the same
// display note even when boxed
let mut b = Box::new(foo);
b = Box::new(bar);
//~^ ERROR mismatched types
//~| different fn items have unique types, even if their signatures are the same
// suggest removing reference
let c: fn(u32) -> u32 = &foo;
//~^ ERROR mismatched types
//~| expected fn pointer `fn(_) -> _`
//~| found reference `&fn(_) -> _ {foo}`
// suggest using reference
let d: &fn(u32) -> u32 = foo;
//~^ ERROR mismatched types
//~| expected reference `&fn(_) -> _`
//~| found fn item `fn(_) -> _ {foo}`
// suggest casting with reference
let e: &fn(u32) -> u32 = &foo;
//~^ ERROR mismatched types
//~| expected reference `&fn(_) -> _`
//~| found reference `&fn(_) -> _ {foo}`
// OK
let mut z: fn(u32) -> u32 = foo as fn(u32) -> u32;
z = bar;
}
|
