diff options
Diffstat (limited to 'src/test/ui/extern/extern-types-thin-pointer.rs')
-rw-r--r-- | src/test/ui/extern/extern-types-thin-pointer.rs | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/ui/extern/extern-types-thin-pointer.rs b/src/test/ui/extern/extern-types-thin-pointer.rs new file mode 100644 index 000000000..b85fc4886 --- /dev/null +++ b/src/test/ui/extern/extern-types-thin-pointer.rs @@ -0,0 +1,42 @@ +// run-pass +#![allow(dead_code)] +// Test that pointers and references to extern types are thin, ie they have the same size and +// alignment as a pointer to (). +#![feature(extern_types)] + +use std::mem::{align_of, size_of}; + +extern "C" { + type A; +} + +struct Foo { + x: u8, + tail: A, +} + +struct Bar<T: ?Sized> { + x: u8, + tail: T, +} + +fn assert_thin<T: ?Sized>() { + assert_eq!(size_of::<*const T>(), size_of::<*const ()>()); + assert_eq!(align_of::<*const T>(), align_of::<*const ()>()); + + assert_eq!(size_of::<*mut T>(), size_of::<*mut ()>()); + assert_eq!(align_of::<*mut T>(), align_of::<*mut ()>()); + + assert_eq!(size_of::<&T>(), size_of::<&()>()); + assert_eq!(align_of::<&T>(), align_of::<&()>()); + + assert_eq!(size_of::<&mut T>(), size_of::<&mut ()>()); + assert_eq!(align_of::<&mut T>(), align_of::<&mut ()>()); +} + +fn main() { + assert_thin::<A>(); + assert_thin::<Foo>(); + assert_thin::<Bar<A>>(); + assert_thin::<Bar<Bar<A>>>(); +} |