const reference must be initialized in constructor base/member initializer list
I am trying to block access to the default constructor of a class I am writing. The constructor I want others to use requires a const reference to another object. I have made the default constructor private to prevent others from using it. I am getting a compiler error for the default constructor because the const reference member variable is not initialized properly. What can I do t开发者_开发知识库o make this compile?
class CFoo
{
public:
CFoo();
~CFoo();
};
class CBar
{
public:
CBar(const CFoo& foo) : fooReference(foo)
{
}
~CBar();
private:
const CFoo& fooReference;
CBar() // I am getting a compiler error because I don't know what to do with fooReference here...
{
}
};
don`t declare default constructor. It is not available anyway (automatically that it's) if you declare your own constructor.
class CBar
{
public:
CBar(const CFoo& foo) : fooReference(foo)
{
}
private:
const CFoo& fooReference;
};
fairly comprehensive explanation of constructors can be found here: http://www.parashift.com/c++-faq-lite/ctors.html
The easiest way to create the default constructor you don't wanna use (that is the case with your constructor, is that right?) is just not defining it, that is:
class CBar
{
public:
CBar(const CFoo& foo) : fooReference(foo)
{
}
~CBar();
private:
const CFoo& fooReference;
CBar();
};
In this case, it may be a little superfluous, because the compiler will not create a default constructor for a class with a reference member, but it's better to put it there in case you delete the reference member.
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