Specifically, I would like to create an Array class and would like to overload the  operator.
Yes. For example, there is
__radd__. Also, there are none for
__ge__(), etc., but as Joel Cornett rightly observes, if you define only
a > b calls the
__lt__ function of
b, which provides a workaround.
>>> class My_Num(object): ... def __init__(self, val): ... self.val = val ... def __radd__(self, other_num): ... if isinstance(other_num, My_Num): ... return self.val + other_num.val ... else: ... return self.val + other_num ... >>> n1 = My_Num(1) >>> n2 = 3 >>> >>> print n2 + n1 4 >>> print n1 + n2 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for +: 'My_Num' and 'int'
Note that in at least some cases it's reasonable to do something like this:
>>> class My_Num(object): ... def __init__(self, val): ... self.val = val ... def __add__(self, other_num): ... if isinstance(other_num, My_Num): ... return self.val + other_num.val ... else: ... return self.val + other_num ... __radd__ = __add__
No, it is not possible. C does not support operator overloading by the developer.
In "C" language, operators have different meaning when they are used as prefix to expression, suffix to expression or "infix" (between two expressions).
Consider '*', which performs multiplication as 'infix' operator, and pointer indirection when used as a prefix. Similarily, the '-' operator, which performs subtraction as 'infix' operator, and negation when used as a prefix.
Basically, it's not about overriding, it if the operator appears between two expressions, or as a prefix to a single expression.
In the same way, The "C" compiler knows if the '&' is bit-wise and, or address-of, based on it's position is the expression: If it is between two expressions, it's the AND, if it is before an expression, it is 'address-of'.
See https://en.wikipedia.org/wiki/Infix_notation about infix.
There is no
++ operator in Python (nor '--'). Incrementing is usually done with the
+= operator instead.
If you are using PHP5 (and you should be), take a look at the SPL ArrayObject classes. The documentation isn't too good, but I think if you extend ArrayObject, you'd have your "fake" array.
EDIT: Here's my quick example; I'm afraid I don't have a valuable use case though: