macro_rules! assert_not_impl_all {
($x:ty: $($t:path),+ $(,)?) => { ... };
}
Expand description
Asserts that the type does not implement all of the given traits.
This can be used to ensure types do not implement auto traits such as
Send
and Sync
, as well as traits with blanket impl
s.
Note that the combination of all provided traits is required to not be
implemented. If you want to check that none of multiple traits are
implemented you should invoke assert_not_impl_any!
instead.
Examples
Although u32
implements From<u16>
, it does not implement Into<usize>
:
assert_not_impl_all!(u32: From<u16>, Into<usize>);
The following example fails to compile since u32
can be converted into
u64
.
ⓘ
assert_not_impl_all!(u32: Into<u64>);
The following compiles because Cell
is not both Sync
and Send
:
use std::cell::Cell;
assert_not_impl_all!(Cell<u32>: Sync, Send);
But it is Send
, so this fails to compile:
ⓘ
assert_not_impl_all!(Cell<u32>: Send);