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Diffstat (limited to 'vendor/bytemuck/tests/doc_tests.rs')
-rw-r--r-- | vendor/bytemuck/tests/doc_tests.rs | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/vendor/bytemuck/tests/doc_tests.rs b/vendor/bytemuck/tests/doc_tests.rs new file mode 100644 index 0000000..d08e970 --- /dev/null +++ b/vendor/bytemuck/tests/doc_tests.rs @@ -0,0 +1,123 @@ +#![allow(clippy::disallowed_names)] + +//! Cargo miri doesn't run doctests yet, so we duplicate these here. It's +//! probably not that important to sweat keeping these perfectly up to date, but +//! we should try to catch the cases where the primary tests are doctests. +use bytemuck::*; + +// Miri doesn't run on doctests, so... copypaste to the rescue. +#[test] +fn test_transparent_slice() { + #[repr(transparent)] + struct Slice<T>([T]); + + unsafe impl<T> TransparentWrapper<[T]> for Slice<T> {} + + let s = Slice::wrap_ref(&[1u32, 2, 3]); + assert_eq!(&s.0, &[1, 2, 3]); + + let mut buf = [1, 2, 3u8]; + let _sm = Slice::wrap_mut(&mut buf); +} + +#[test] +fn test_transparent_basic() { + #[derive(Default)] + struct SomeStruct(u32); + + #[repr(transparent)] + struct MyWrapper(SomeStruct); + + unsafe impl TransparentWrapper<SomeStruct> for MyWrapper {} + + // interpret a reference to &SomeStruct as a &MyWrapper + let thing = SomeStruct::default(); + let wrapped_ref: &MyWrapper = MyWrapper::wrap_ref(&thing); + + // Works with &mut too. + let mut mut_thing = SomeStruct::default(); + let wrapped_mut: &mut MyWrapper = MyWrapper::wrap_mut(&mut mut_thing); + let _ = (wrapped_ref, wrapped_mut); +} + +// Work around miri not running doctests +#[test] +fn test_contiguous_doc() { + #[repr(u8)] + #[derive(Debug, Copy, Clone, PartialEq)] + enum Foo { + A = 0, + B = 1, + C = 2, + D = 3, + E = 4, + } + unsafe impl Contiguous for Foo { + type Int = u8; + const MIN_VALUE: u8 = Foo::A as u8; + const MAX_VALUE: u8 = Foo::E as u8; + } + + assert_eq!(Foo::from_integer(3).unwrap(), Foo::D); + assert_eq!(Foo::from_integer(8), None); + assert_eq!(Foo::C.into_integer(), 2); + assert_eq!(Foo::B.into_integer(), Foo::B as u8); +} + +#[test] +fn test_offsetof_vertex() { + #[repr(C)] + struct Vertex { + pos: [f32; 2], + uv: [u16; 2], + color: [u8; 4], + } + unsafe impl Zeroable for Vertex {} + + let pos = offset_of!(Zeroable::zeroed(), Vertex, pos); + let uv = offset_of!(Zeroable::zeroed(), Vertex, uv); + let color = offset_of!(Zeroable::zeroed(), Vertex, color); + + assert_eq!(pos, 0); + assert_eq!(uv, 8); + assert_eq!(color, 12); +} + +#[test] +fn test_offsetof_nonpod() { + #[derive(Default)] + struct Foo { + a: u8, + b: &'static str, + c: i32, + } + + let a_offset = offset_of!(Default::default(), Foo, a); + let b_offset = offset_of!(Default::default(), Foo, b); + let c_offset = offset_of!(Default::default(), Foo, c); + + assert_ne!(a_offset, b_offset); + assert_ne!(b_offset, c_offset); + // We can't check against hardcoded values for a repr(Rust) type, + // but prove to ourself this way. + + let foo = Foo::default(); + // Note: offsets are in bytes. + let as_bytes = &foo as *const _ as *const u8; + + // We're using wrapping_offset here because it's not worth + // the unsafe block, but it would be valid to use `add` instead, + // as it cannot overflow. + assert_eq!( + &foo.a as *const _ as usize, + as_bytes.wrapping_add(a_offset) as usize + ); + assert_eq!( + &foo.b as *const _ as usize, + as_bytes.wrapping_add(b_offset) as usize + ); + assert_eq!( + &foo.c as *const _ as usize, + as_bytes.wrapping_add(c_offset) as usize + ); +} |