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// Copyright 2014 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.
// pretty-expanded FIXME #23616
#![feature(core)]
extern crate core;
use core::nonzero::NonZero;
use std::mem::size_of;
use std::rc::Rc;
use std::sync::Arc;
trait Trait { fn dummy(&self) { } }
fn main() {
// Functions
assert_eq!(size_of::<fn(isize)>(), size_of::<Option<fn(isize)>>());
assert_eq!(size_of::<extern "C" fn(isize)>(), size_of::<Option<extern "C" fn(isize)>>());
// Slices - &str / &[T] / &mut [T]
assert_eq!(size_of::<&str>(), size_of::<Option<&str>>());
assert_eq!(size_of::<&[isize]>(), size_of::<Option<&[isize]>>());
assert_eq!(size_of::<&mut [isize]>(), size_of::<Option<&mut [isize]>>());
// Traits - Box<Trait> / &Trait / &mut Trait
assert_eq!(size_of::<Box<Trait>>(), size_of::<Option<Box<Trait>>>());
assert_eq!(size_of::<&Trait>(), size_of::<Option<&Trait>>());
assert_eq!(size_of::<&mut Trait>(), size_of::<Option<&mut Trait>>());
// Pointers - Box<T>
assert_eq!(size_of::<Box<isize>>(), size_of::<Option<Box<isize>>>());
// The optimization can't apply to raw pointers
assert!(size_of::<Option<*const isize>>() != size_of::<*const isize>());
assert!(Some(0 as *const isize).is_some()); // Can't collapse None to null
struct Foo {
_a: Box<isize>
}
struct Bar(Box<isize>);
// Should apply through structs
assert_eq!(size_of::<Foo>(), size_of::<Option<Foo>>());
assert_eq!(size_of::<Bar>(), size_of::<Option<Bar>>());
// and tuples
assert_eq!(size_of::<(u8, Box<isize>)>(), size_of::<Option<(u8, Box<isize>)>>());
// and fixed-size arrays
assert_eq!(size_of::<[Box<isize>; 1]>(), size_of::<Option<[Box<isize>; 1]>>());
// Should apply to NonZero
assert_eq!(size_of::<NonZero<usize>>(), size_of::<Option<NonZero<usize>>>());
assert_eq!(size_of::<NonZero<*mut i8>>(), size_of::<Option<NonZero<*mut i8>>>());
// Should apply to types that use NonZero internally
assert_eq!(size_of::<Vec<isize>>(), size_of::<Option<Vec<isize>>>());
assert_eq!(size_of::<Arc<isize>>(), size_of::<Option<Arc<isize>>>());
assert_eq!(size_of::<Rc<isize>>(), size_of::<Option<Rc<isize>>>());
// Should apply to types that have NonZero transitively
assert_eq!(size_of::<String>(), size_of::<Option<String>>());
}
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