Re: Question about function template(from Thinking in C++ book)

"Igor Tandetnik" <>
Sun, 19 Jul 2009 00:32:01 -0400
chrisben wrote:

  Here are sample codes from Thinking in C++ Vol I, page 776

// A function template:
template<class Iter>
void drawAll(Iter start, Iter end) {
while(start != end) {

What I do not understand is line

If Iter is a pointer, should that be start->draw(), instead of

Obviously, Iter is intended to be analogous to a double pointer - a
pointer into a collection of pointers to objects (perhaps smart
pointers). Something along the lines of:

class Shape {
  virtual void draw() = 0;

class Circle : public Shape {
  void draw();

class Square : public Shape {
  void draw();

vector<Shape*> shapes;
shapes.push_back(new Circle);
shapes.push_back(new Square);

drawAll(shapes.begin(), shapes.end());

With best wishes,
    Igor Tandetnik

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necessarily a good idea. It is hard to be sure where they are going to
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