What does : mean?

Question

I have 2 classes:

class base {     virtual void foo() {}; };  class derived : public base {     void foo() { base::foo(); } }; 

I made a mistake and wrote base:foo(); instead of base::foo();. The code was compiled and run, but segfaulted.

I don't know how I can Google it and don't know what it is, but I'm very interested: what does that mean?

base:foo(); 

If it is important:

class base : public QAbstractGraphicsShapeItem 

Answer 1

void foo() { base:foo(); } 

is equivalent to:

void foo() {    base: // An unused label.    foo(); // Calls the function again, resulting in infinite recursion. } 

Due to infinite recursion, the function causes stack overflow.