opIndex operators

[gedaiu]

Hi again!

I don't understand why we have opIndex() and opIndexAssign()... 
can anyone explain this for me?

Because in c++ there is only one operator overload for "[]" and 
it looks like this:

Value& Value::operator[] (constValue offset) {
	return container[offset];
}

and with this operator overload I can set or get values from 
container, and also easily implement custom multilevel arrays.

In D when I have this method

Value& opIndex(Value index) {
	return container[index];
}

I get this error.

Error: no identifier for declarator Value
Error: semicolon expected, not '&'
Declaration expected, not '&'

And also, how you can implement custom structs that acts like a 
multilevel array in D like in c++?

Thanks!