Macro core_extensions::parenthesize_args

macro_rules! parenthesize_args {
    (
        $(:: $(@$leading:tt@)? )? $first:ident $(:: $trailing:ident)* ! { $($prefix:tt)* }

        $($extra:tt)*
    ) => { ... };
}

Available on crate feature macro_utils only.

Adaptor macro which passes arguments to a callback macro, wrapping them in parentheses.

Example

use core_extensions::{count_tts, parenthesize_args};
 
 
fn main() {
    assert_eq!(foo(), 5);
}
 
macro_rules! the_macro {
    ($func:ident $count:literal) => {
        pub fn $func() -> u32 { $count }
    }
}

// `parenthesize_args` invokes `count_tts` here,
// then `count_tts` counts `a b c d e` as having 5 tokens,
// passing `5` as the `$count` parameter to `the_macro`.
parenthesize_args!{
    count_tts!{
        the_macro!{foo}
    }
    a b c d e
}