fix_fn

This library enables the creation of recursive closures by providing a single macro fix_fn. The functionality is similar to the Y combinator. Recursive closures can have arbitrary amounts of parameters and can capture variables.

``` use fixfn::fixfn; let fib = fix_fn!(|fib, i: u32| -> u32 { if i <= 1 { i } else { // fib will call the closure recursively fib(i - 1) + fib(i - 2) } });

assert_eq!(fib(7), 13); ```