Just to show an example (not using Signals2), where we can
self-destruct a Functor:
This is unsafe (disaster) code.
///////////////////////////////////////////////////////////////////
#include <iostream>
#include <map>
#include <functional>
#include <algorithm>
using namespace std;
using FuncSig = void();
using Func = function<FuncSig>;
class Functor {
public:
Functor(map *m_, const string &key_) : m{m_},
key{key_} { cout << "Functor() " << key << endl; }
Functor(const Functor &other) : m{other.m}, key{other.key} { cout <<
"Functor(const Functor &other) " << key << endl; }
~Functor() { cout << "~Functor() " << key << endl; }
void operator()() const {
cout << " this == " << this << endl;
cout << " key == " << key << endl;
auto it = m->find(key);
if (it != m->cend()) {
m->erase(it); // self-destruct
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
}
cout << " still running code from class (if constructor has
already run, we're in deep trouble... accessing destructed data...)"
<< endl;;
cout << " this == " << this << endl;
cout << " key == " << key << endl;
}
private:
map *m;
const string key;
};
int main()
{
map m;
auto x = m.emplace("hello", Functor(&m, "hello"));
x.first->second();
return 0;
}
///////////////////////////////////////////////////////////////////
