rust/tests/ui/closures/issue-868.rs
许杰友 Jieyou Xu (Joe) 8da09aed94
Add allow-by-default lint for unit bindings
This lint is not triggered if any of the following conditions are met:

- The user explicitly annotates the binding with the `()` type.
- The binding is from a macro expansion.
- The user explicitly wrote `let () = init;`
- The user explicitly wrote `let pat = ();`. This is allowed for local
  lifetimes.
2023-11-20 11:45:44 +08:00

20 lines
451 B
Rust

// run-pass
#![allow(unused_parens)]
#![allow(unit_bindings)]
// pretty-expanded FIXME #23616
fn f<T, F>(g: F) -> T where F: FnOnce() -> T { g() }
pub fn main() {
let _x = f( | | { 10 });
// used to be: cannot determine a type for this expression
f(| | { });
// ditto
f( | | { ()});
// always worked
let _: () = f(| | { });
// empty block with no type info should compile too
let _ = f(||{});
let _ = (||{});
}