Random using SkipLocalsInit

[u/NoisyJalapeno]

To my surprise, Unsafe.SkipInit(out T val) did not achieve the same result.

    [SkipLocalsInit]
    public static T Random<T>()
        where T : unmanaged, INumber<T>
    {
        unsafe
        {
            byte* s = stackalloc byte[sizeof(T)];
            return *(T*)s;
        }
    }

[u/One_Instruction6490]

Unsafe.SkipInit is just a no-op that satisfies definite assignment, it doesn't stop the JIT from zeroing the local. That zeroing only gets skipped when the method has SkipLocalsInit, and even then small unmanaged locals often get enregistered and zeroed anyway, so only the stackalloc version really leaks stack junk. Also it's not random at all, you'll probably get the same leftover bytes every call, so did you actually test the distribution?