From 1b6a04ca5504955c571d1c97504fb45ea0befee4 Mon Sep 17 00:00:00 2001 From: Valentin Popov Date: Mon, 8 Jan 2024 01:21:28 +0400 Subject: Initial vendor packages Signed-off-by: Valentin Popov --- vendor/bytemuck/tests/offset_of_tests.rs | 60 ++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 vendor/bytemuck/tests/offset_of_tests.rs (limited to 'vendor/bytemuck/tests/offset_of_tests.rs') diff --git a/vendor/bytemuck/tests/offset_of_tests.rs b/vendor/bytemuck/tests/offset_of_tests.rs new file mode 100644 index 0000000..4cad5d4 --- /dev/null +++ b/vendor/bytemuck/tests/offset_of_tests.rs @@ -0,0 +1,60 @@ +#![allow(clippy::disallowed_names)] +use bytemuck::{offset_of, Zeroable}; + +#[test] +fn test_offset_of_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_offset_of_foo() { + #[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 + ); +} -- cgit v1.2.3