src/test/ui/inference/question-mark-type-infer.rs

   1 // Test that type inference fails where there are multiple possible return types
   2 // for the `?` operator.
   3
   4 fn f(x: &i32) -> Result<i32, ()> {
   5     Ok(*x)
   6 }
   7
   8 fn g() -> Result<Vec<i32>, ()> {
   9     let l = [1, 2, 3, 4];
  10     l.iter().map(f).collect()?
  11     //~^ ERROR type annotations needed
  12 }
  13
  14 fn main() {
  15     g();
  16 }