src/test/ui/consts/rvalue-static-promotion.rs

   1 // run-pass
   2
   3 use std::cell::Cell;
   4
   5 const NONE_CELL_STRING: Option<Cell<String>> = None;
   6
   7 struct Foo<T>(#[allow(unused_tuple_struct_fields)] T);
   8 impl<T> Foo<T> {
   9     const FOO: Option<Box<T>> = None;
  10 }
  11
  12 fn main() {
  13     let _: &'static u32 = &42;
  14     let _: &'static Option<u32> = &None;
  15
  16     // We should be able to peek at consts and see they're None.
  17     let _: &'static Option<Cell<String>> = &NONE_CELL_STRING;
  18     let _: &'static Option<Box<()>> = &Foo::FOO;
  19 }