C++ remove_if on a vector of objects

Question

I have a vector (order is important) of objects (lets call them myobj class) where I\'m trying to delete multiple objects at a time.

class vectorList
{

             


        

Answer 1

A predicate is basically a conditional comparison. It can be a function or object. Here's an example using new C++ lambdas. This code will go through the vector and remove the values equal to 3.

int arg[6] = {1, 2, 3, 3, 3, 5};
std::vector vec(arg, arg+6);
vec.erase(
   std::remove_if(
      vec.begin(), vec.end(),
      [](int i){ return i == 3;}),
   vec.end());

Edit: For pointers let's say you had a vector or interfaces you could set them to nullptr then remove them in a batch with pretty much the same code. In VS2008 you won't have lambdas so make a comparison predicate function or struct instead.

bool ShouldDelete(IAbstractBase* i)
{
    return i == nullptr;
    // you can put whatever you want here like:
    // return i->m_bMarkedDelete;
}

std::vector vec;
vec.erase(
   std::remove_if(
      vec.begin(), vec.end(),
      ShouldDelete),
   vec.end());