Given a variable or an object, then print the memory state. The MSB is on the left and the LSB is on the right.

cast2bits.cpp

#include <iostream>
#include <string>
#include <sstream>
#include <bitset>
#include <typeinfo>

using namespace std;

class cast2bits {
private:
    struct bits {
        unsigned char b7 : 1;
        unsigned char b6 : 1;
        unsigned char b5 : 1;
        unsigned char b4 : 1;
        unsigned char b3 : 1;
        unsigned char b2 : 1;
        unsigned char b1 : 1;
        unsigned char b0 : 1;
    };
    int length;
    ostringstream oss;
    ostringstream data;

public:
    template<class T>
    explicit cast2bits(const T &input) {
        data << input << " type: " << typeid(input).name();
        const T *pTInput = &input;
        auto *pBitsinput = (bits *) pTInput;
        int n = sizeof(T) / sizeof(bits);
        length = 9 * n - 1;
        for (int i = n - 1; i >= 0; --i) {
            oss << (int) ((pBitsinput + i)->b0)
                << (int) ((pBitsinput + i)->b1)
                << (int) ((pBitsinput + i)->b2)
                << (int) ((pBitsinput + i)->b3)
                << (int) ((pBitsinput + i)->b4)
                << (int) ((pBitsinput + i)->b5)
                << (int) ((pBitsinput + i)->b6)
                << (int) ((pBitsinput + i)->b7)
                << ' ';
        }
    }

    friend ostream &operator<<(ostream &os, const cast2bits &c) {
        os << c.data.str() << endl;
        os << "M" << string((unsigned long long int) (c.length - 2), ' ') << "L" << endl;
        os << c.oss.str() << endl;
        return os;
    }
};


int main() {
    cout << cast2bits(123) << endl;
    cout << cast2bits((long long) 123) << endl;
    cout << cast2bits(123.0f) << endl;
    cout << cast2bits(123.0) << endl;
    cout << cast2bits('3') << endl;
    cout << cast2bits("123") << endl;
    cout << cast2bits(string("123")) << endl;
    cout << cast2bits(bitset<66>().set());
    return 0;
}

/* output:
123 type: i
M                                 L
00000000 00000000 00000000 01111011

123 type: x
M                                                                     L
00000000 00000000 00000000 00000000 00000000 00000000 00000000 01111011

123 type: f
M                                 L
01000010 11110110 00000000 00000000

123 type: d
M                                                                     L
01000000 01011110 11000000 00000000 00000000 00000000 00000000 00000000

3 type: c
M      L
00110011

123 type: A4_c
M                                 L
00000000 00110011 00110010 00110001

123 type: NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
M                                                                                                                                                                                                                                                                                             L
00000000 00000000 00000000 00000000 01101111 11001010 01100110 11001101 00000000 00000000 00000000 00000000 00000000 00110011 00110010 00110001 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000011 00000000 00000000 00000000 00000000 00000000 01100010 11111011 00010000

111111111111111111111111111111111111111111111111111111111111111111 type: St6bitsetILy66EE
M                                                                                                         L
00000000 00000000 00000000 00000011 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111
*/