question-mark-type-infer.rs

// Test that type inference fails where there are multiple possible return types
// for the `?` operator.

fn f(x: &i32) -> Result<i32, ()> {
    Ok(*x)
}

fn g() -> Result<Vec<i32>, ()> {
    let l = [1, 2, 3, 4];
    l.iter().map(f).collect()?
    //~^ ERROR type annotations needed
}

fn main() {
    g();
}

// ferrocene-annotations: fls_pocsh1neugpc
// Error Propagation Expression
//
// ferrocene-annotations: fls_izdv9i4spokw
// Operator Expressions