| // Copyright 2017 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. |
| |
| use std::cell::Cell; |
| |
| const NONE_CELL_STRING: Option<Cell<String>> = None; |
| |
| struct Foo<T>(T); |
| impl<T> Foo<T> { |
| const FOO: Option<Box<T>> = None; |
| } |
| |
| fn main() { |
| let _: &'static u32 = &42; |
| let _: &'static Option<u32> = &None; |
| |
| // We should be able to peek at consts and see they're None. |
| let _: &'static Option<Cell<String>> = &NONE_CELL_STRING; |
| let _: &'static Option<Box<()>> = &Foo::FOO; |
| } |