Question

I have a class which basically is a text manager. It can draw text and whatnot. I basically want the color and text std::string to only be a constant reference. Would it then be alright to do

class TextManager {
const std::string &text;
void draw(const std::string &text) const;
public:
TextManager(const std::string &text)
{
  this->text = text;
}

void someMethod()
{
   draw(text);
}


};

I want when the class that owns an instance of TextManager’s text changes, the change is reflected in the TextManager.

would I be better off using a pointer?
thanks

Answer 1

This code doesn’t compile. this->text = text doesn’t do what you think it does – it’s not like Java where assigning a reference is like changing the pointer. reference = value will actually invoke the copy operator, so it will copy the value of the rhs to the lhs, either as member-by-member copy or using the operator= if it was overridden. Since your text is const, you can’t do that.

So in this case, you have to use a pointer – references cannot be modified once initialized.

EDIT: Just to explain ways in which you could use a reference:

const std::string &text = yourString;

or:

TextManager(const std::string &textRef)
: text(textRef)
{
}

That way, you have a permanent reference to whatever string you have.