CODEWITHSUNDEEP
c++stderaseerase-remove-idiom
fishfood
fishfood

Reputation: 4282

Should I be using erase-remove idiom here?

I have an std::vector<IRenderable*> (_pBkBuffer in the code below). It contains a number of static objects (at the start of the vector) that don't change, followed by a variable number of dynamic objects.

// erase-remove, but leave the static renderables intact
_pBkBuffer->erase( 
    std::remove(
        _pBkBuffer->begin() + _nStatics, _pBkBuffer->end(), ???
    ), 
    _pBkBuffer->end() 
);

What can I put at the ??? in order to erase-remove the non-static renderables?

I know that the ??? should match all objects in the specified subset.

Should I be using erase-remove at all, or should I use another approach?

Upvotes: 2

Views: 317

Answers (1)

jrok
jrok

Reputation: 55395

'Should I be using erase-remove at all

Aparently you already know where the object are, so no. You do this:

_pBkBuffer->erase( _pBkBuffer->begin() + _nStatics, _pBkBuffer->end() );

or, even better:

_pkBuffer->resize( _nStatics );

Erase remove idiom would be used if you had them scattered randomly in the vector. What's missing instead of ??? is a value that elements to be removed are compared to. Since you're storing pointers, you'd most likely need to provide a custom predicate (a function pointer, functor, or a lambda) and use remove_if instead.

Upvotes: 4

Related Questions