如何解释从<typeinfo>图书馆？

Question

Q1 - Since both begin(arr) & &arr will return hexadecimal pointer location of starting of the arr , wondering what is the difference between the outputs of data types printed by the following script?

#include <iostream>
#include <typeinfo>
#include <string>

using namespace std;

int main()
{
    int arr[] = {10, 20, 30, 40, 50, 60, 77};

    cout << typeid(begin(arr)).name() << " , " << typeid(&arr).name() << endl;
    cout << begin(arr) << " , " << &arr << endl;

    return 0;
}

OUTPUT

Pi , PA7_i
0x7ffc79a99500 , 0x7ffc79a99500

Q2 - how can we get decimal representation of hex pointer location?

Answer 1

For Q1:

Note that begin(arr) and &arr are different things (with different types). begin(arr) gives the pointer to the 1st element of arr with type int* , &arr gives the pointer to the array arr with type int (*)[7] .