C++ deletion from vector
Author
I don't understand where this code doesn't work, I know that isDead() returns true when I hit the enemy but the destructor for the object never gets called.
for ( int i=0; i<mEntityList.size(); ++i )
{
mEntityList->update();
if ( mEntityList->isDead() )
{
mEntityList.erase(mEntityList.begin()+i);//Delete dead people.
//delete mEntityList;
}
}
I commented out my other way of deleting cause it didn't work either.
You are erasing the element from the vector, then deleting a (unrelated) entity.
Instead, either delete first, or save the pointer and delete afterwards:
Note you can use [source][/source] or [code][/code] to preserve the formatting of posted code.
[edit:
I forgot to make the increment conditional. I usually use std::remove_if() which is a better algorithm to use:
Instead, either delete first, or save the pointer and delete afterwards:
for ( int i = 0 ; i < mEntityList.size() ; ){ Entity *entity = mEntityList; entity->update(); if ( entity->isDead() ) { mEntityList.erase(mEntityList.begin()+i);//Delete dead people. delete entity; } else { ++i; }}Note you can use [source][/source] or [code][/code] to preserve the formatting of posted code.
[edit:
I forgot to make the increment conditional. I usually use std::remove_if() which is a better algorithm to use:
#include <algorithm>struct UpdateAndDeleteDeadEntities{ bool operator()(Entity *entity) { entity->update(); bool dead = entity->isDead(); if(dead) { delete entity; } return dead; }};// whereever your code wasmEntityList.erase( std::remove_if(mEntityList.begin(), mEntityList.end(), UpdateAndDeleteDeadEntities()), mEntityList.end() );
Two problems I see:
1. Assuming the elements in the vector are objects created with new, you need to delete them.
2. You're erasing elements in the vector as you iterate through it - you'll miss elements in the vector.
This should work:
1. Assuming the elements in the vector are objects created with new, you need to delete them.
2. You're erasing elements in the vector as you iterate through it - you'll miss elements in the vector.
This should work:
for (std::vector<Entity*>::iterator it=mEntityList.begin(); it!=mEntityList.end();){ Entity* pEntity = *it; pEntity->update(); if(pEntity->isDead()) { it = mEntityList.erase(it); // Remove from the vector delete pEntity; // Delete the entity and free memory } else ++it;}std::for_each(mEntityList.begin(), mEntityList.end(), std::mem_fun(&Entity::update));mEntityList.erase(std::remove_if(mEntityList.begin(), mEntityList.end(), std::mem_fun(&Entity::isDead)), mEntityList.end());That doesn't do any deletion, though. Consider using smart pointers instead. You'll need to make wrapper functions to call the update and isDead functions (since std::mem_fun is expecting a raw pointer), but the basic logic is the same.
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