tests/ui/type/type-ascription.rs

//@ run-pass

#![allow(dead_code, unused_variables, unused_assignments)]

// Type ascription doesn't lead to unsoundness
#![feature(type_ascription)]

use std::mem;

const C1: u8 = type_ascribe!(10, u8);
const C2: [u8; type_ascribe!(1, usize)] = [1];

struct S {
    a: u8
}

fn main() {
    assert_eq!(type_ascribe!(C1.into(), i32), 10);
    assert_eq!(C2[0], 1);

    let s = S { a: type_ascribe!(10, u8) };
    let arr = &[1u8, 2, 3];

    let mut v = type_ascribe!(arr.iter().cloned().collect(), Vec<_>);
    v.push(4);
    assert_eq!(v, [1, 2, 3, 4]);

    let a = type_ascribe!(1, u8);
    let b = type_ascribe!(a.into(), u16);
    assert_eq!(v[type_ascribe!(a.into(), usize)], 2);
    assert_eq!(mem::size_of_val(&a), 1);
    assert_eq!(mem::size_of_val(&b), 2);
    assert_eq!(b, type_ascribe!(1, u16));

    let mut v = Vec::new();
    type_ascribe!(v, Vec<u8>) = vec![1, 2, 3]; // Place expression type ascription
    assert_eq!(v, [1u8, 2, 3]);
}