how to Validate if iterator is not empty???

[Helder Lopes]

i have this iterator:

 std::list<entanim_s>::iterator iterAnim

and i want to validate with this iterator is not empty

i have this code but vs dont compile.

if(iterAnim != NULL)
{	
    iterAnim->ePriority = priority;
}

why? what the reason for this???
what is the best way to do this???

[Inanna]

There is no way to test if an iterator is uninitialized, but you can initialize it to the end() of your container as a default invalid value:

std::list<entanim_s>::iterator iterAnim = my_list.end();

if (iterAmin != my_list.end())
{
    iterAnim->ePriority = priority;
}

[tabstop]

An iterator cannot be empty. The list could be empty, or iterAnim could be invalid.

The official position seems to be that it's your job to make sure iterAnim is always valid. Always initialize your iterators, and if you do something destructive that might invalidate your iterator, make sure you set it to something known good.

[Helder Lopes]

so this code

if(iterAnim != NULL)
{	
    iterAnim->ePriority = priority;
}

is impossible to be valid??

[tabstop]

That can't really work, correct. iterAnim is not really a pointer and can't be NULL.

[Helder Lopes]

thanks for the fast aswers....