Macro str_format

macro_rules! str_format {
    ($ty_size:ty, $($args:tt)*) => { ... };
}

creates a formated string of given type (by implementing core::fmt::Write):

   let s = str_format!(str8,"abc{}{}{}",1,2,3);
   assert_eq!(s,"abc123");

will truncate if capacity exceeded, without warning. See try_format! for version that does not truncate.