Macro sewup_derive::fn_sig

fn_sig!() { /* proc-macro */ }

fn_sig helps you get you function signature

1. provide function name to get function signature from the same namespace, which function should be decorated with #[ewasm_fn], for example, fn_sig!(the_name_of_contract_handler)

2. provide a function name with input parameters then the macro will calculate the correct functional signature for you. ex: fn_sig!(the_name_of_contract_handler( a: i32, b: String ))