format_all_args 0.1.0

format_all_args 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.

When optional_arg is used as an argument to format_all_args, additional parentheses must be used.

main.rs

use format_all_args::{format_all_args, optional_arg};

fn main() {
    macro_rules! optional_arg_test { ( $($a:expr)? ) => { optional_arg!($($a)?) }; }
    //                                 ----------^                      -----^
    //                                 optional                         optional
    //
    let result = format!("{}", format_all_args!(1,2,3,4,5,(optional_arg_test!( )),7));
    //                                                    ^                   ^ ^
    //                                                    |                     |
    //                                                    +---------------------+
    //                                                    additional parentheses
    assert_eq!(result, "123457");
}