Macro power_of_two::power_of_two

macro_rules! power_of_two {
    #[proc_macro_hack] => { ... };
}

Raises 2 to the power of provided exp.

use power_of_two::power_of_two;

const POW_2: usize = power_of_two!(2);
const POW_2_isize: isize = power_of_two!(2, isize);