Java: Using generics to implement a class that operates on different kinds of numbers
generics, java
Solution
Uh oh---generics are not C++ templates. Because of type erasure, the `Double` in your example won't even show through to the runtime system.
In your particular case, if you just want to be able to add various types together, may I suggest method overloading? e.g., `double add(double, double)`, `float add(float, fload)`, `BigDecimal add(BigDecimal, BigDecimal)`, etc.
Problem
So, let's say I want to write a class that operates on different kinds of numbers, but I don't a priori know what kind of numbers (i.e. ints, doubles, etc.) I will be operating on. I would like to use generics to create a general class for this scenario. Something like: ``` Adder<Double> adder = new Adder<Double>(); adder.add(10.0d, 10.0d); // = 20.0d ``` But, I cannot instantiate the generic type I pass in to my Adder class! So -- what to do?