:: What does it mean in C + +

(1) indicates "domain Operator"

Example: Declares a Class A, Class A declares a member function void F (), but does not give the definition of F in the declaration of the class, so when F is defined outside the class,

will be written as void A::f (), which indicates that the F () function is a member function of class A.

(2) Directly before the global function, which means the global function

Example: In the VC, you can call the API function, in front of the API functions:

(3) Representing reference member functions and variables, scope member operators

Example: System::math::sqrt () equivalent to SYSTEM.MATH.SQRT ()

:: What does it mean in C + +