“在所有控制路径上递归，函数将导致运行时堆栈溢出”，重载<<运算符

Question

I have a section of code that seems to have a recursive warning when I compile, any ideas why?

ostream& operator << (ostream& out, const node& rhs)
    {
        out << rhs.get_data();
        return out;
    }

It is calling this function:

node::value_type node::get_data() const
    {
        return data;
    }

Answer 1

This is just a guess, since you haven't posted a self-contained example. In particular, the definition of node would be very useful.

I think that, for some reason, the compiler is choosing to convert rhs.get_data() into a node , probably using an implicit conversion constructor, rather than selecting an overload of operator<< that takes node::value_type . You should:

• Make sure that operator << (ostream&, node::value_type) has been declared before your definition of operator<<
• If node has a constructor that takes value_type , then it's probably best to make it explicit to avoid unexpected implicit conversions.