macro_rules! code_material_function { ( fn $name:ident ( $( $arg_name:ident : $arg_type:tt ),* ) -> $ret_type:tt { $code:literal } ) => { ... }; }
macro_rules! code_material_function { ( fn $name:ident ( $( $arg_name:ident : $arg_type:tt ),* ) -> $ret_type:tt { $code:literal } ) => { ... }; }