How to sum generic numbers in C#? [duplicate]

Answer 1

You can do it with "little magic" from LINQ:

private static readonly Func adder;
static NumberContainer() {
    var p1 = Expression.Parameter(typeof (T));
    var p2 = Expression.Parameter(typeof (T));
    adder = (Func)Expression
        .Lambda(Expression.Add(p1, p2), p1, p2)
        .Compile();
} 
public T Total { get { return adder(ValueA, ValueB); } }

The only drawback is that this code will compile even if NumberContainer is instantiated with a type T that does not support addition; of course it will throw an exception at run-time. An added benefit is that this should work with user-defined + operators.