Macro assert_impl 

assert_impl!() { /* proc-macro */ }

A simple macro for making compile-time assertions that a type implements a given trait.

This macro supports generic parameters via for<...> syntax and trait bounds via where ... syntax.

Examples

use assert_impl_trait::assert_impl;

// Assert that `u8` implements `Clone`.
assert_impl!(u8: Clone);

// Assert that for any type `T` that implements `Clone`, `Vec<T>` also
// implements `Clone`.
assert_impl!(
    for<T: Clone> {
        Vec<T>: Clone,
    }
);

// Assert that for any type `T` and any integer `N`:
// - If `T` implements `Clone`, `[T; N]` also implements `Clone`.
// - If `T` implements `Copy`, `[T; N]` also implements `Copy`.
// - If `T` is valid for a lifetime, `[T; N]` is also valid for it.
assert_impl!(
    for<T, const N: usize> {
        where T: Clone {
            [T; N]: Clone,
        }
        where T: Copy {
            [T; N]: Copy,
        }

        for<'a> where T: 'a {
            [T; N]: 'a,
        }
    }
);

// Assert that `Debug` is a dyn-compatible trait.
assert_impl!(dyn core::fmt::Debug:);