recursive equal, and firstDifference functions

[timotheecour]

> And how do you even have the concept of recursion without some 
> sort of range or container to recursively iterate through?

It's not hard: I've done it for a serialization library I've been 
working on (which has some advantages over std.orange, such as 
serializing to json/binary etc. more on this later), as well as 
for my toStringRecurse: it works on any data type roughly as 
follows:

auto equalRecurse(T)(T a) {
static if isAssociativeArray!(T)) {
}
else static if(isArray!(T)) {
}
else static if(is(T == struct) ){
foreach(i, member; a.tupleof) {
...
}
else static if...
}

>> Expecting the compiler to automagically figure out how to 
>> compare two types for you is just begging for trouble

I beg to differ. I like to be as lazy as possible when writing 
user code (as opposed to library code). The compiler can do a lot 
of stuff automagically in D thanks to CT reflection. I didn't run 
into problems when using the serialization on rather complex 
nested objects.