如何在另一个成员函数中用常量返回类型修改成员函数的返回值？

Question

The title seems contradictory, and perhaps it is. But this is the problem I am trying to tackle in C++ 11. I am creating a binary search tree, and the search functions looks something like this:

const node* search(char);

I have made the return type constant as I do not want the tree to be arbitrarily changed by outside functions(I am returning node* to allow traversals), but I am also using this function in the remove() function to find the node to be deleted. I want the returned value to be modifiable by the remove() member function.

The obvious solution seems to be: create a private search function with a non constant return type, but that seems to unnescessarily lengthen the code.

Is there another way to do this, or achieve a similar functionality?

Answer 1

You can easily do this to avoid the code duplication:

class foo {
public:
    const node* search(char c) const { return internal_search(c); } 
private:
    node* internal_search(char c) const { 
        // actual implementation
    } 
};