Question

In an effort to write better code, I’ve committed to using boost’s smart pointers.

Should a boost::shared_ptr always be initialized like so?

boost::shared_ptr<TypeX> px(new TypeX);

My confusion has risen from a code block similar to this:

void MyClass::FillVector()
{
    boost::shared_ptr<TypeX> tempX;
    if(//Condition a)
    {
        boost::shared_ptr<TypeX> intermediateX(new TypeA);
        tempX = intermediateX;
    }
    else
    {
        boost::shared_ptr<TypeX> intermediateX(new TypeB);
        tempX = intermediateX;
    }
    _typeXVec.push_back(tempX); // member std::vector< boost::shared_ptr<TypeX> >
}

Is there an accepted way to skip that intermediate shared_ptr while keeping it in scope to push back to _typeXVec?

Thank you.

Edit: Wanted to clarify that TypeA and TypeB are both children of TypeX.

Answer 1

boost::shared_ptr<X> p;
if( condition ) {
  p.reset( new A() );
}else {
  p.reset( new B() );
}