How C# 11 static abstract members in interfaces enable universal numeric algorithms:

public static T SumArray<T>(ReadOnlySpan<T> numbers) where T : INumber<T>
{
    T total = T.Zero;
    foreach (T n in numbers)
        total += n;
    return total;
}

// Works on int, float, double, decimal, Half, BigInteger, and custom types!
int sumInt = SumArray<int>([1, 2, 3, 4]);
double sumDouble = SumArray<double>([1.5, 2.5, 3.5]);

The JIT compiler monomorphizes generic math calls into native CPU assembly with zero boxing and zero interface dispatch overhead!

Static abstract interface members (INumber<T>, IFloatingPoint<T>) solved a 20-year limitation in C# where generic operators like + and * were impossible.

Clean, type-safe, and generates identical machine code to hand-written scalar arithmetic.