formatallargs macro

Formats any number of arguments without heap allocation.

Additionally, the library provides macro optional_arg which may be required when programming macros with optional arguments.

main.rs

```rust use formatallargs::{formatallargs, optional_arg};

fn main() { macrorules! optionalargtest { ( $($a:expr)? ) => { optionalarg!($($a)?) }; } // ----------^ -----^ // optional optional // let result = format!("{}", formatallargs!(1,2,3,4,5,optionalargtest!( ),7)); assert_eq!(result, "123457"); } ```