primitive brainfuck interpreter

#include <iostream>
#include <string>
#include <vector>

using namespace std;

class BrainfuckInterpreter {

public:

    explicit BrainfuckInterpreter(const string& instructions)
        : instructions(instructions), memory(30000) { }

    void execute() {

        auto the_pointer = memory.data();

        for(char instruction : instructions) {

            switch(instruction) {

            case '>':
                ++the_pointer;
                break;

            case '<':
                --the_pointer;
                break;

            case '+':
                ++*the_pointer;
                break;

            case '-':
                --*the_pointer;
                break;

            case '.':
                cout << *the_pointer;
                break;

            case ',':
                cin >> *the_pointer;
                break;

            }

        }

    }

private:

    string instructions;
    vector<unsigned char> memory;

};

int main() {

    string instructions;
    cin >> instructions;

    BrainfuckInterpreter interpreter(instructions);
    interpreter.execute();

}