Way to check for leaks manually?

[ArpatronEvilDrac]

Is there some manner of fashion I can check if I'm inadvertently leaking? I mean, I can't tell if this is bad:

    private static method Check takes nothing returns boolean
        return not IsUnitAlly(GetAttacker(), GetOwningPlayer(GetTriggerUnit()))/*
        */and GetUnitAbilityLevel(GetTriggerUnit(), ABIL_ID) >= 1 /*
        */and ValidGroundTarget(GetAttacker(), GetTriggerUnit())
    endmethod

compared to this:

    private static method Check takes nothing returns boolean
        local unit attacker = GetAttacker()
        local unit attacked = GetTriggerUnit()
        if not IsUnitAlly(attacker, GetOwningPlayer(attacked))/*
        */and GetUnitAbilityLevel(attacked, ABIL_ID) >= 1 /*
        */and GetUnitAbilityLevel(attacked, REAL_ID) >= 1/*
        */and ValidGroundTarget(attacker, attacked) /*
        */and IsUnitInRange(attacker, attacked, RANGE) then
            call CounternovaData.create()
        endif
        set attacker = null
        set attacked = null
        return false
    endmethod

Basically, I know you need to remove/destroy/then null anything not integer, real, boolean or string, right? Does .destroy() a struct work correctly for ALL the variables or do say, units need removed from inside an .onDestroy() method? That's what I've been doing just for safe sake.

I'd just like to know if the wc3 memory usage will change or anything that can alert me to whether I did something wrong or right exists. I remove and null all my handles that I'm aware of, but I'm not sure whether I missed something...

 

[chobibo]

Leaks are associated with local variables pointing to handle type objects, that after being used, is not set to point to null. Global variables can also cause leaks but the global variable is not lost unlike the local one.

The game engine's garbage collector only releases memory occupied by an object when the said memory has no existing reference (a variable, can be global or local) to it.

A variable (in jass), specifically handle types, are pointers to objects in memory (units, timers, groups, triggers, etc.). Local variables, if behaving properly, should have been removed from memory once the function returns, but this does not happen in jass, that's why the local variables persist after the function where it was created has already ended. It exists still, but it is unreachable, and because it points to an object, the garbage collector will not return the memory used by the said object.

I hope I remember it correctly though.

 

[deathismyfriend]

The way you have both of the functions is fine. The second is preferable as it is both faster and more efficient.
If you are only returning a boolean then use the first function.
If you are calling functions from inside the function use the second function you have.