Function NUM2LONG 

pub unsafe fn NUM2LONG(obj: VALUE) -> c_long

Convert Ruby Integer to long (akin to NUM2LONG).

Converts any Ruby Integer (Fixnum or Bignum) to a C long. May raise a RangeError exception if the value is out of range.

Safety

• obj must be a valid Integer VALUE
• May call into Ruby runtime and potentially raise exceptions
• May trigger garbage collection