Macro json_ffi_binary 

macro_rules! json_ffi_binary {
    ($name:ident, $input1_type:ty, $input2_type:ty, | $arg1:ident, $arg2:ident | $body:expr_2021) => { ... };
}

Creates a FFI-compatible function that takes two JSON strings as input, deserializes them to two arguments, applies a body of logic, and returns the result as a JSON string.