Hash function for floats

Question

I\'m currently implementing a hash table in C++ and I\'m trying to make a hash function for floats...

I was going to treat floats as integers by padding the decimal

Answer 1

unsigned hash(float x)
{
    union
    {
        float f;
        unsigned u;
    };
    f = x;
    return u;
}

Technically undefined behavior, but most compilers support this. Alternative solution:

unsigned hash(float x)
{
    return (unsigned&)x;
}

Both solutions depend on the endianness of your machine, so for example on x86 and SPARC, they will produce different results. If that doesn't bother you, just use one of these solutions.