is there a way, to access a class member variable from within a struct member function defined within this class?
Atm, the only solution that comes to my mind would be to add fProperty to struct S as well and initialize S.fProperty with A.fProperty (or add a reference to the parenting class) when creating an instance of S but that does not seem to ideal to me.

Thanks a lot already for your help and let me know if I can make this post more clear (first post here).

class A {
    struct S {
        void funcS(float theNumber) {if (theNumber > XXXfProperty) {// do sth}}    
    };
    A(float theProperty):(fProperty(theProperty)){}
    void funcA(){
        S s;        
        s.funcS(complicatedFunction());  
    }
    float fProperty; // want to access this number from all instances of S I create somewhere within class A implementation.
};

int main(){
    A a1(1.); 
    A a2(10.);
}

Source: Windows Questions C++