D language unsigned hash of string - hash

Question

I am a complete beginner with the D language.
How to get, as an uint unsigned 32 bits integer in the D language, some hash of a string...
I need a quick and dirty hash code (I don't care much about the "randomness" or the "lack of collision", I care slightly more about performance).
import std.digest.crc;
uint string_hash(string s) {
return crc320f(s);
}
is not good...
(using gdc-5 on Linux/x86-64 with phobos-2)

Answer 1

While Adams answer does exactly what you're looking for, you can also use a union to do the casting.
This is a pretty useful trick so may as well put it here:
/**
* Returns a crc32Of hash of a string
* Uses a union to store the ubyte[]
* And then simply reads that memory as a uint
*/
uint string_hash(string s){
import std.digest.crc;
union hashUnion{
ubyte[4] hashArray;
uint hashNumber;
}
hashUnion x;
x.hashArray = crc32Of(s); // stores the result of crc32Of into the array.
return x.hashNumber; // reads the exact same memory as the hashArray
// but reads it as a uint.
}

Answer 2

A really quick thing could just be this:
uint string_hash(string s) {
import std.digest.crc;
auto r = crc32Of(s);
return *(cast(uint*) r.ptr);
}
Since crc32Of returns a ubyte[4] instead of the uint you want, a conversion is necessary, but since ubyte[4] and uint are the same thing to the machine, we can just do a reinterpret cast with the pointer trick seen there to convert types for free at runtime.