Example

class MyClass
{
public:
MyClass(int init){
var = init;
}
int getVar(){
return var;
}
private:
int var;
};

int function(int input){
MyClass mc(10);

if(10 == input){
return mc.getVar();
}
else{
return 0;
}

}
Solution
Save the return value to a variable and return that instead.

class MyClass
{
public:
MyClass(int init){
var = init;
}
int getVar(){
return var;
}
private:
int var;
};

int function(int input){
MyClass mc(10);

if(10 == input){
int tmp = mc.getVar();
return tmp;
}
else{
return 0;
}

}