Macro impl_fmt_traits

macro_rules! impl_fmt_traits {
    ($name:ident, $native:ident, "floating point number") => { ... };
    ($name:ident, $native:ident, "unsigned integer") => { ... };
    ($name:ident, $native:ident, "signed integer") => { ... };
    ($name:ident, $native:ident, @all_types) => { ... };
}