Why D is annoying =P

[Mehrdad]

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.