Possibility to add instances of generic types in Java 8

Question

I want to implement some algorithm:

public class MaximumSubarrayAlgorithm<TArray extends List<T>, T extends Comparable<T>> 
{

public void DoSmth(TArray simple) {

    T t1 = simple.get(0);
    T t2 = simple.get(1);

    t1 = t1 + t2; // wrong: The operator + is undefined for the argument type(s) T, T

    return null;
}

}

How to require possibility to add instances of type parameters (and tell it to java compiler)? May be T is not Integer, it may be some other type, that support addition.

What are you trying to add? What is 'simple.get()'? Can you include more information. — Forseth11, Apr 20 '15 at 22:08
This is impossible since Java doesn't support operator overloading. — Luiggi Mendoza, Apr 20 '15 at 22:08
defining your own operators doesn't work in java if im not wrong , you'd have to make methods like .add() — vlatkozelka, Apr 20 '15 at 22:09

score 1 · Accepted Answer · answered Apr 20 '15 at 22:09

1

This is not supported in Java. You cannot use + on objects whose types you don't know, except to perform string concatenation; Java does not support operator overloading.

answered Apr 20 '15 at 22:09

Louis Wasserman

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Workaround? Use concrete types? And rewrite algorithm, for example, for matrices? – Alex T Apr 20 '15 at 22:13
Yeah, use concrete types. Make your matrix data structure attached specifically to doubles or ints or whatever; don't try to generify it to different number types. – Louis Wasserman Apr 20 '15 at 22:25

Possibility to add instances of generic types in Java 8

1 Answers1