Trouble using iterator for collision

[averagejoeprogrammer]

Hi,

I am having some troubles with the collision detection within SFML I have a Vector of skeletons
std::vector<Skeleton> *skeletons = new std::vector<Skeleton>();

I am then trying to test whether or not the main character intersects with the any of the enemies I am trying to do this using a iterator.

for (std::vector<Skeleton>::iterator it = skeletons->begin(); it != skeletons->end(); ++it)
       {
              if (mainCharacter->mSprite.getGlobalBounds().intersects(it->mSprite.getGlobalBounds()))
              {
                     /*skeletons->erase(skeletons->begin() + *it);*/
                     skeletons->erase(*it);
              }
       }

Do you have any idea what I am doing wrong here?

Kind Regards

[Laurent]

The right way to erase elements of a vector while iterating over them can easily be found with Google, it's a very common "problem".

[averagejoeprogrammer]

I tried changing this too
skeletons->erase(skeletons->begin() + it);

but the error I get is
   51   IntelliSense: no operator "+" matches these operands
            operand types are: std::_Vector_iterator<std::_Vector_val<std::_Simple_types<Skeleton>>> + std::_Vector_iterator<std::_Vector_val<std::_Simple_types<Skeleton>>>

so I then tried it this way
skeletons->erase(it);
Error   7   error C2582: 'operator =' function is unavailable in 'Skeleton'   c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility   

Any ideas what is going wrong here? I appreciate this is probably very simple problem but I tried various solutions from google to no avail.

[ka0s420]

with a vector instead of using an iterator i'd use a normal for loop. at which point it would just be erase(i).

 

for (int i = 0; i < skeletons.size(); i++)
       {
              if (mainCharacter->mSprite.getGlobalBounds().intersects(skeletons[i]->mSprite.getGlobalBounds()))
              {
                     /*skeletons->erase(skeletons->begin() + *it);*/
                     skeletons->erase(i);
              }
       }

I'm also not sure why you're using new to create the vector. look up RAII or just avoid using a pointer at all.

[Mortal]

erasing an element from std::vector is widely covered in net. the most elegant way to achieve it by using STL approach, just  try to search for erase–remove idiom.

[Laurent]

Since people seem to prefer trying random stuff than clicking the first answer on Google... here it is

(generic version, adapt to your code)

for (auto it = v.begin(); it != v.end(); )
{
    if (some_condition(*it))
        it = v.erase(it);
    else
        ++it;
}

same thing, hidden behind STL functions:

v.erase(std::remove_if(v.begin(), v.end(), [](T item){return some_condition(item);}), v.end());