// run-pass #![allow(dead_code)] #![allow(unused_variables)] // 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) = vec![1, 2, 3]; // Place expression type ascription assert_eq!(v, [1u8, 2, 3]); }