I work on my course with C ++, and wanted to use a Python class variable access feature. Here's an example:
class Telefone:
nums = {}
def __init__(self, numero):
self.num = numero
Telefone.nums[numero] = self
print(list(Telefone.nums))
joao = Telefone(40028922)
paulo = Telefone(30302020)
pedro = Telefone(55677655)
Output:
[40028922]
[40028922, 30302020]
[40028922, 30302020, 55677655]
How do I do this in C ++?
I think there is no simple way to implement this in C ++. Certain features of languages such as Python can only be expressed in C ++ with complicated hacks or logic. But you could do so:
#include <iostream>
#include <string>
#include <unordered_map>
using namespace std;
class Telefone
{
using num_map = unordered_map<string, Telefone>;
static num_map nums;
public:
Telefone() { }
Telefone(const string& numero)
{
nums[numero] = *this;
Print();
}
void Print()
{
cout << "[ ";
for (const auto& num : nums)
cout << num.first << " ";
cout << "]\n";
}
};
Telefone::num_map Telefone::nums;
int main()
{
Telefone joao("40028922");
Telefone epaulo("30302020");
Telefone pedro("55677655");
std::getchar();
return 0;
}
If I were you, I would try to write this in a simpler way using C ++ features rather than trying to imitate Python behavior. Note: I have used string to represent the number because the Visual C ++ hash table implementation (% w / o%) fails to keep the order of values with integers.