On our project, which is primarily written in C++, I have the above
problem in our Ruby bindings. We generate a simple Ruby API using SWIG
 and I maintain a more Ruby-like layer on top of that.
One of our APIs, in C++, expects to take in a uint8_t type as an
argument. In the Ruby code I’m not sure what type should be passed in. A
Fixnum results in $SUBJECT (the value I used was 7) and I’m not sure how
to force the value to be something only 8 bits in length.