rust/tests/ui/transmutability/abstraction/const_generic_fn.rs

41 lines
891 B
Rust

//@ check-pass
//! An array must have the correct length.
#![crate_type = "lib"]
#![feature(transmutability)]
#![allow(dead_code, incomplete_features, non_camel_case_types)]
mod assert {
use std::mem::{Assume, TransmuteFrom};
pub fn array_like<T, E, const N: usize>()
where
T: TransmuteFrom<[E; N], { Assume::SAFETY }>,
[E; N]: TransmuteFrom<T, { Assume::SAFETY }>
{}
}
fn len_0() {
type Array = [u8; 0];
#[repr(C)] struct Struct();
assert::array_like::<Struct, u8, 0>();
}
fn len_1() {
type Array = [u8; 1];
#[repr(C)] struct Struct(u8);
assert::array_like::<Struct, u8, 1>();
}
fn len_2() {
type Array = [u8; 2];
#[repr(C)] struct Struct(u8, u8);
assert::array_like::<Struct, u8, 2>();
}
fn len_3() {
type Array = [u8; 3];
#[repr(C)] struct Struct(u8, u8, u8);
assert::array_like::<Struct, u8, 3>();
}