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violating strict weak ordering std::sort

CPlahPlahLearner (53)
Getting the common segfault with this operator function (the function is really simple. It's just this long because it repeats some conditions.):
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bool operator() (objcopy * lhs, objcopy * rhs)
{
	if (lhs->deleteobj&&rhs->deleteobj) //no
	{
		if (lhs->rndrngpriority!=rhs->rndrngpriority)
		{
		        return lhs->rndrngpriority > rhs->rndrngpriority;
		}
		else if (lhs->posz != rhs->posz)
		{
		        return lhs->posz < rhs->posz;
		}
		else if (lhs->_universal_id != rhs->_universal_id)
			return lhs->_universal_id > rhs->_universal_id;
		else
			return false;
	}
	if (!lhs->deleteobj && rhs->deleteobj)
	{
		return false;
	}
	if (lhs->deleteobj && !rhs->deleteobj)
	{
		return true;
	}
	if (lhs->rndrbackid!=NONE && rhs->rndrbackid!=NONE )
	{
		if (lhs->rndrngpriority!=rhs->rndrngpriority)
		{
		        return lhs->rndrngpriority > rhs->rndrngpriority;
		}
		else if (lhs->posz != rhs->posz)
		{
		        return lhs->posz < rhs->posz;
		}
		else if (lhs->_universal_id != rhs->_universal_id)
		{
			return lhs->_universal_id > rhs->_universal_id;
		}
		else
		{
			return false;
		}
	}
	if (lhs->rndrbackid != NONE && rhs->rndrbackid == NONE )
	{
		return false;
	}
	if (lhs->rndrbackid == NONE && rhs->rndrbackid != NONE )
	{
		return true;
	}
	if (lhs->isbar != rhs->isbar)
	{
		if (lhs->isbar)
			return true;
		if (rhs->isbar)
			return false;
	}        
	else
	{
		if (lhs->rndrngpriority!=rhs->rndrngpriority)
		{
		        return lhs->rndrngpriority > rhs->rndrngpriority;
		}
		else if (lhs->posz != rhs->posz)
		{
		        return lhs->posz < rhs->posz;
		}
		else if (lhs->_universal_id != rhs->_universal_id)
		{
		        return lhs->_universal_id > rhs->_universal_id;
		}
		else
		{
		        return false;
		}
	}
}


Each of these objects has a unique "_universal_id" value, and even in case (even though I don't see how that would happen) the object was compared to itself, the function returns false as it should.

"NONE" is a magic number which is just interpreted as no value.

Thanks in advance!
Last edited on
cire (8284)
Each of these objects have a unique "_universal_id" value,


In some cases, the return value has nothing to do with this _universal_id value, so how is that relevant?
CPlahPlahLearner (53)
I am aware of that, but the comparison involving that member is what happens in the worst scenarios. When I stated that each object has a unique value of that member, I wanted to disregard the property of "irreflexivity" ( as 2 objects will never be the same unless you're comparing the object to itself, which, even though I can't see why std::sort would compare an object to itself, would return False anyway).

Now I just can't see where I screwed up >.<.
MiiNiPaa (8886)
What line execution stops on?
CPlahPlahLearner (53)
Once the segfault is thrown, I am taken to line 68 (where the zpos members are compared).

I am aware one can't try/catch segfault errors, but is there a way I can catch the problem before the segfault happens?
ne555 (10692)
I'm not understanding,
you consciously created a not strict weak ordering and wonder why the sort fails
or you observed that the sort fails, and blame it to the comparison function.

> the function is really simple
explain it.


By the way, ¿can you post the minimal amount of code needed to reproduce your problem?
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