Macro cookie_factory::gen_cond

macro_rules! gen_cond {
    (($i:expr, $idx:expr), $cond:expr, $submac:ident!( $($args:tt)* )) => { ... };
    (($i:expr, $idx:expr), $cond:expr, $f:expr) => { ... };
}

gen_cond!(bool, I -> Result<I,E>) => I -> Result<I,E> Conditional combinator

Wraps another generator and calls it if the condition is met. This combinator returns the return value of the child generator.