(sub)Class compare && Instance compare

[Barbie]

By trying to enable multiple teams in MH and walking through the code I found the following UT99 stock code which confuses me:

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class Translocator extends TournamentWeapon;

var TranslocatorTarget TTarget;
[...]

function bool HandlePickupQuery( inventory Item )
{
	if ( Item.IsA('TranslocatorTarget') && (item == TTarget) )
	[...]
}

If the condition item == TTarget is True then the condition Item.IsA('TranslocatorTarget') is always true so that the clause can be reduced to item == TTarget. Is the original clause just redundant or did I run into a pitfall here?

[Wormbo]

Reference equality implies type equality. If you really only care about whether you see the same thing, you don't have to check its type at all, because you already know it.

Also, a word about that IsA() function: Don't use it.
It doesn't provide any compile-time type-safety or sanity validation whatsoever. If you want to check an instance's type, do a typecast-null check (i.e. "TranslocatorTarget(Item) != None"), because then the compiler can already tell you when there's a typo in the class name or when your check can never work out as the specified type and the variable's type are unrelated to each other. Also note that IsA() is a function call like any other and thus can bring up Accessed none errors at runtime, unlike a typecast operation.

[Barbie]

IsA() function: Don't use it.
It doesn't provide any compile-time type-safety or sanity validation whatsoever.

Yes, I've seen things like this in foreign code:

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if(Killer.IsA('ScreptedPawn') && Other.IsA('ScreptedPawn'))return;

If you want to check an instance's type, do a typecast-null check

That's a nice alternative, thanks for the hint.

[JackGriffin]

Depending on the usage this check works very well also

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  if(Item.Class==Class'Whatever')

Also you'll find

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if(Killer.IsA('ScreptedPawn') && Other.IsA('ScreptedPawn'))return;

in my MH controllers. I know it's a misprint from when I copied and learned from UTJMH. The original coder was Japanese and I just liked it so much I left it in. It's certainly not a valid class.