Better example:
private import std.traits, std.typecons, std.typetuple;
hash_t toHash(T)(in T t)
if (isIntegral!(T) || isSomeChar!(T))
{ return t; }
hash_t toHash(T)(in T[] t)
{
typeof(return) h = 0;
foreach (item; t)
{ h = (h * 37) ^ item.toHash(); }
return h;
}
hash_t toHash(V, K)(in V[K] t)
{
typeof(return) h = 0;
foreach (k, v; t)
{ h ^= k.toHash(); }
return h;
}
hash_t toHash(T)(in T t)
if (!isIntegral!(T) &&
!isSomeChar!(T) &&
!isArray!(T) &&
!isAssociativeArray!(T))
{
typeof(return) h = 0;
foreach (ref a; t.tupleof)
{ h = (h * 37) ^ a.toHash(); }
return h;
}
void main()
{
import std.stdio;
writeln(tuple("hi", [[1: 2].keys.dup], [1: 2, 8: 4]).toHash());
writeln(tuple("hi", [[1: 2].keys.dup], [1: 2, 8: 4]).toHash());
// same thing as above
}
We really _need_ something like this in Phobos IMHO.
