🚀 go-pugleaf

a2675528@athena.rrz.Uni-Koeln.DE (Paul Sponagl) writes:

>>	template < class T >
>>	void swap(T & item1, T & item2)
>>	{
>>		T temp = item1;
>>		item1 = item2;
>>		item2 = temp;
>>	}

>or do like that

>	inline template < class T > void swap(T& a, T& b) 
>	{
>		a ^=b; b^=a;a ^=b;
>	}

I had hoped that this old idea was dead, but I guess it isn't.

First of all, the code will compile only if operator^= is available.
For built-in types, this is true only for the integer types. You
can't swap floats, doubles, or pointers, for example.

Secondly, it doesn't always give the correct answer. Here is
a simple test case:

	int i = 2;
	cout << i << endl; // prints '2'
	swap(i, i); 
	cout << i << endl; // prints '0'

The original template works for all types which have assignment
defined. Every type can be assigned unless you take steps to
prevent it.
--
Steve Clamage, stephen.clamage@eng.sun.com