Modifying a pointer pointer field from a method - c++

Question

I'm trying to modify a bool field in a method. The method accepts a pointer pointer bool, but can't seem to figure it out how to do this correctly.
This is a basic example of something similar I want to do:
class WarningManager {
bool seenWarningA;
void updateWarnings() {
pushWarning(&seenWarningA)
}
void pushWarning(bool ** warning) {
**warning = true;
}
}
This code example errors (sending bool* but needs to be bool**) and I've tried other ways with no luck. Can't find any online examples but maybe I'm searching for the wrong terms. What is the right way to do this?

Answer 1

Since you have a class, no parameters are required.
class WarningManager {
bool seenWarningA;
void updateWarnings() {
pushWarning()
}
void pushWarning() {
seenWarningA = true;
}
}
Using references rather than pointers is more elegant.
class WarningManager {
bool seenWarningA;
void updateWarnings() {
pushWarning(seenWarningA)
}
void pushWarning(bool & warning) {
warning = true;
}
}
If you want to use pointers, the & operator just gives single pointer rather than a double point:
class WarningManager {
bool seenWarningA;
void updateWarnings() {
pushWarning(&seenWarningA)
}
void pushWarning(bool * warning) {
*warning = true;
}
}

Answer 2

You appear to be trying to pass an argument of bool* into a function that takes bool**. Remove one of the layers of indirection from the parameter list, or add one to the value you're passing in. Either should work.

Answer 3

Two mistakes:
First- your declaration of pushWarning is with parameter of type bool**, and you are trying to send bool*.
Second- you can simply use reference:
using namespace std;
class WarningManager {
public:
bool seenWarningA;
void updateWarnings() {
pushWarning(seenWarningA);
}
void pushWarning(bool &warning) { // You can simply use refference instead of pointer to pointer, or pointer at all..
warning = true;
}
};
int main()
{
WarningManager w;
w.seenWarningA = false;
w.updateWarnings();
cout << w.seenWarningA; // Prints 1
return 0;
}