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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/structs-enums/enum-layout-optimization.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/ui/structs-enums/enum-layout-optimization.rs')
-rw-r--r-- | src/test/ui/structs-enums/enum-layout-optimization.rs | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/test/ui/structs-enums/enum-layout-optimization.rs b/src/test/ui/structs-enums/enum-layout-optimization.rs new file mode 100644 index 000000000..05d297906 --- /dev/null +++ b/src/test/ui/structs-enums/enum-layout-optimization.rs @@ -0,0 +1,50 @@ +// run-pass +// Test that we will do various size optimizations to enum layout, but +// *not* if `#[repr(u8)]` or `#[repr(C)]` is passed. See also #40029. + +#![allow(dead_code)] + +use std::mem; + +enum Nullable<T> { + Alive(T), + Dropped, +} + +#[repr(u8)] +enum NullableU8<T> { + Alive(T), + Dropped, +} + +#[repr(C)] +enum NullableC<T> { + Alive(T), + Dropped, +} + +struct StructNewtype<T>(T); + +#[repr(C)] +struct StructNewtypeC<T>(T); + +enum EnumNewtype<T> { Variant(T) } + +#[repr(u8)] +enum EnumNewtypeU8<T> { Variant(T) } + +#[repr(C)] +enum EnumNewtypeC<T> { Variant(T) } + +fn main() { + assert!(mem::size_of::<Box<i32>>() == mem::size_of::<Nullable<Box<i32>>>()); + assert!(mem::size_of::<Box<i32>>() < mem::size_of::<NullableU8<Box<i32>>>()); + assert!(mem::size_of::<Box<i32>>() < mem::size_of::<NullableC<Box<i32>>>()); + + assert!(mem::size_of::<i32>() == mem::size_of::<StructNewtype<i32>>()); + assert!(mem::size_of::<i32>() == mem::size_of::<StructNewtypeC<i32>>()); + + assert!(mem::size_of::<i32>() == mem::size_of::<EnumNewtype<i32>>()); + assert!(mem::size_of::<i32>() < mem::size_of::<EnumNewtypeU8<i32>>()); + assert!(mem::size_of::<i32>() < mem::size_of::<EnumNewtypeC<i32>>()); +} |