Example C++ class that demonstrates combined declaration and definition of class within single file.

test.cpp

#include <algorithm>
#include <iostream>
#include <string>

using namespace std;

class Test {
   public:
    Test(string name) : name(fixName(name)) {}

    friend Test operator+(Test& lhs, Test& rhs) {
        string str = lhs.name + rhs.name;
        random_shuffle(str.begin(), str.end());
        return Test(str);
    }

    friend ostream& operator<<(ostream& os, const Test& t) {
        os << t.name;
        return os;
    }

    friend istream& operator>>(istream& is, Test& t) {
        is >> t.name;
        return is;
    }

    static string fixName(string name) {
        // convert string to lower case
        for (string::iterator it = name.begin(); it < name.end(); it++) {
            *it = tolower(*it);
        }

        // make the first character upper case
        name[0] = toupper(name[0]);

        return name;
    }

   private:
    string name;
};

int main() {
    cout << endl;

    Test t("Fred");
    cout << "New Test named " << t << endl;

    cout << "Enter new name for " << t << ": ";
    cin >> t;
    cout << "Test now named " << t << endl;

    cout << endl;

    Test s("George");
    cout << "Another new Test named " << s << endl;

    cout << t << " + " << s << " = " << t + s << endl;

    cout << endl;
}