Dereferencing an iterator of a list of pointers

Question

I have a problem trying to dereference an iterator of a std::list<std::unique_ptr<MyClass>>. Here's my situation: in headerFile.h I have

class MyClass{
public:
   bool variable = false;
private:
};

and then in headerFile2.h

#include "headerFile.h"
#include <memory>
#include <list>
class OtherClass{
public:
private:
   std::list<std::unique_ptr<MyClass>> MyList;
   void MyFuction();
};

and, finally, in headerFile2.cpp I try to use MyClass::variable like this:

#include "headerFile2.h"
void OtherClass::MyFunction(){
   for(auto it = MyList.begin(); it != MyList.end(); it++){
      *it -> variable = true;
   }
}

It won't compile and I don't know where my mistake is. The error message is 'struct std::_List_iterator<std::unique_ptr<MyClass> >' has no member named 'variable'

I also tried doing **it.variable = true;.

I would appreciate any advice.

Answer 1

operator-> has higher precedence than operator*, so *it -> variable = true; is interpreted as *(it -> variable) = true;, while it -> variable is invalid.

You can add parentheses as

(*it) -> variable = true;

**it.variable = true; has the similar issue; you could (**it).variable = true;.