Macro keys 

macro_rules! keys {
    (@to_unit $($_:tt)*) => { ... };
    (@count $($tail:expr),*) => { ... };
    [$($key: expr),* $(,)?] => { ... };
}

A convenience macro for passing a set of keys. Keys don’t have the same type, so regular Vecs don’t work.

Example Usage

client.invalidate_queries(keys![("hello", "World"), "test", ("user", 3)]);