Simple leak question

[Omni]

Well i have one question,

I cant really explain what i mean so i will use an example:

function Doesthisleak takes location Do_I_Leak returns nothing
    call CreateUnitAtLoc(Player(0), 'hfoo', Do_I_Leak, 0.00)
    call RemoveLocation(Do_I_Leak)
endfunction

function Omni takes nothing returns nothing
    call Doesthisleak(GetRectCenter(GetWorldBounds()))
endfunction

Does 'Do_I_Leak' leak?

 

[Doom-Angel]

i think it does since u are still calling a location which is not framed in a variable but from the other side that value goes stright to the function u call so it's realy is confusion though....
so im gonna join ur question.

 

[substance]

dunno.

Why cant you use coordinates?

 

[PurgeandFire]

Parameters do NOT leak.

Parameters don't leak so you don't need to do anything about them.

 

[Sim]

The location has to be created somehow, and if you don't remove it...

 

[PurgeandFire]

The location has to be created somehow, and if you don't remove it...

Well, that's the point it is used, eg:

function Location takes location l returns nothing
    call KillUnit(u)
endfunction

function JASS takes nothing returns nothing
    local location l = GetUnitLoc(GetTriggerUnit())
    call Location(l)
    call RemoveLocation(l)
    set l = null
endfunction

^
|
-- That won't leak.

 

[SFilip]

Code from the first post - doesn't leak.
However I discourage making functions this way from a simple reason

function Omni takes nothing returns nothing
    local location l = GetUnitLoc(someunit)
    call Doesthisleak(l)
    call CreateUnitAtLoc(Player(0), 'hfoo', l, 0.00)
endfunction

It doesn't leak, but the second unit will most likely appear at the center of the map since l is destroyed at that point.
Nothing really wrong, but this would certainly be confusing for me to work with so I suggest that you avoid fixing leaks this way.

 

[Omni]

Code from the first post - doesn't leak.

But would it if there wasnt a "call RemoveLocation(Do_I_Leak)" in it?
I guess so *looking at ForGroupBJ*

and i know a can avoid leaks a better way, lol this was just an example of what i meant. (anyway ty)

 

[SFilip]

> if there wasnt a "call RemoveLocation(Do_I_Leak)"
Then it would.

Now if you are curious on how this whole thing works...every handle-derived type (units, locations, groups...) is in fact an integer, kind of an address that points to where the actual data is located (in case of units the type, hp, mp, in case of locations the coordinates etc). When you specify a variable like this as a parameter you copy only this address and pass it to the function. This is why they are in fact the same thing, only seemingly stored in different variables.