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// run-pass
// 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>>());
}
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