MIN MAX problem

[janderson]

freeagle wrote:
> Hey all,
> 
> from what I know, there is (currently?) no way of implementing min/max 
> template functions that could dynamically change return type depending 
> on the result of comparison. I think that this problem can be "solved" 
> easily. When used in C++, there is no problem with the return type as 
> min/max are coded as macros. But there is always probability that the 
> result of the min/max will be cast into appropriate type, because 
> variables cant be both float and int at the same time, for example.
> That means, when you write in C++
> 
> float f = 1.0f, result;
> int a = 2;
> result = MAX(f, a);
> 
> the result is cast to float when assignment to the variable is being 
> done. This means you always know of what type you want the result to be.
> I say we could move the casting into the function itself, like this:
> 
> T max(T, U)(T arg1, U arg2)
> {
>     return cast(T) (arg1 > arg2 ? arg1 : arg2);
> }
> 
> and make it a standard that the type of the first argument will always 
> be the returning type of the min/max function.
> 
> Just a thought
> 
> freeagle

In C++ you can use some copy constructor / assignment magic with a proxy 
object to get the task done.  That technique won't handle different 
types in the same query though.

-Joel