File: coerce-unify-return.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, forky, sid, trixie, trixie-backports, trixie-proposed-updates
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (18 lines) | stat: -rw-r--r-- 492 bytes parent folder | download | duplicates (15) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
//@ run-pass
// Check that coercions unify the expected return type of a polymorphic
// function call, instead of leaving the type variables as they were.


struct Foo;
impl Foo {
    fn foo<T>(self, x: T) -> Option<T> { Some(x) }
}

pub fn main() {
    let _: Option<fn()> = Some(main);
    let _: Option<fn()> = Foo.foo(main);

    // The same two cases, with implicit type variables made explicit.
    let _: Option<fn()> = Some::<_>(main);
    let _: Option<fn()> = Foo.foo::<_>(main);
}