Some compilers allows the user to omit constructor definitions where a parent class provides a constructor with parameters. In Microsoft C++, all constructors with parameters must be defined in the derived class, or the compiler cannot find the required constructor. This may mean defining dummy constructors which call parent constructors, for example:
MyClass::MyClass(int x, int y):ParentClass(x, y) { }This is not a problem where the constructor has no parameters.