Macro static_assertions::assert_not_impl_all

macro_rules! assert_not_impl_all {
    ($($xs:tt)+) => { ... };
}

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 impls.

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

On stable Rust, using the macro requires a unique “label” when used in a module scope:

assert_not_impl_all!(ptr0; *const u16, Send, Sync);
assert_not_impl_all!(ptr1; *const u8, Send, Sync);

The labeling limitation is not necessary if compiling on nightly Rust with the nightly feature enabled:

#![feature(underscore_const_names)]

assert_not_impl_all!(&'static mut u8, Copy);

fn main() {
    assert_not_impl_all!(u32, Into<usize>);
}

The following example fails to compile since u32 can be converted into u64.

assert_not_impl_all!(u32, Into<u64>);

Cell<u32> is not both Sync and Send.

assert_not_impl_all!(cell; Cell<u32>, Sync, Send);

But it is Send, so this fails to compile.

assert_not_impl_all!(cell; Cell<u32>, Send);