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Diffstat (limited to '')
-rw-r--r-- | tests/ui/derives/deriving-with-repr-packed-2.rs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tests/ui/derives/deriving-with-repr-packed-2.rs b/tests/ui/derives/deriving-with-repr-packed-2.rs new file mode 100644 index 000000000..79aca74df --- /dev/null +++ b/tests/ui/derives/deriving-with-repr-packed-2.rs @@ -0,0 +1,20 @@ +// Check that deriving certain builtin traits on certain packed structs cause +// errors. To avoid potentially misaligned references, field copies must be +// used, which involves adding `T: Copy` bounds. + +#[derive(Copy, Clone, Default, PartialEq, Eq)] +#[repr(packed)] +pub struct Foo<T>(T, T, T); + +struct NonCopy; + +fn main() { + // This one is fine because `u32` impls `Copy`. + let x: Foo<u32> = Foo(1, 2, 3); + _ = x.clone(); + + // This one is an error because `NonCopy` doesn't impl `Copy`. + let x: Foo<NonCopy> = Foo(NonCopy, NonCopy, NonCopy); + _ = x.clone(); + //~^ ERROR the method `clone` exists for struct `Foo<NonCopy>`, but its trait bounds were not satisfied +} |