// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// Test that we will do various size optimizations to enum layout, but
// *not* if `#[repr(u8)]` or `#[repr(C)]` is passed. See also #40029.

#![allow(dead_code)]

use std::mem;

enum Nullable<T> {
    Alive(T),
    Dropped,
}

#[repr(u8)]
enum NullableU8<T> {
    Alive(T),
    Dropped,
}

#[repr(C)]
enum NullableC<T> {
    Alive(T),
    Dropped,
}

struct StructNewtype<T>(T);

#[repr(C)]
struct StructNewtypeC<T>(T);

enum EnumNewtype<T> { Variant(T) }

#[repr(u8)]
enum EnumNewtypeU8<T> { Variant(T) }

#[repr(C)]
enum EnumNewtypeC<T> { Variant(T) }

fn main() {
    assert!(mem::size_of::<Box<i32>>() == mem::size_of::<Nullable<Box<i32>>>());
    assert!(mem::size_of::<Box<i32>>() < mem::size_of::<NullableU8<Box<i32>>>());
    assert!(mem::size_of::<Box<i32>>() < mem::size_of::<NullableC<Box<i32>>>());

    assert!(mem::size_of::<i32>() == mem::size_of::<StructNewtype<i32>>());
    assert!(mem::size_of::<i32>() == mem::size_of::<StructNewtypeC<i32>>());

    assert!(mem::size_of::<i32>() == mem::size_of::<EnumNewtype<i32>>());
    assert!(mem::size_of::<i32>() < mem::size_of::<EnumNewtypeU8<i32>>());
    assert!(mem::size_of::<i32>() < mem::size_of::<EnumNewtypeC<i32>>());
}