c++ rethrow cases

1.cpp

#include <iostream>
using namespace std;

class except1 {};
class except2 {};

void someFunction() {
    try {
        throw except1();
    } catch(const except1& e) {
        cout << "catched at someFunction\n";

        cout << "rethrowing\n";
        throw except2();    // this will be catched at main not here
        
    } catch(const except2& e2) {
        cout << "this wont be printed\n";
    }
}

int main(int argc, char* argv[]) {
    try {
        someFunction();
    } catch(const except2& e) {
        cout << "catched at main\n";
    }
}

/*output:

catched at someFunction
rethrowing
catched at main
*/

2.cpp

#include <iostream>
using namespace std;

class except1 {};
class except2 {};

void someFunction() {
    try {
        throw except1();
    } catch(const except1& e) {
        cout << "catched at someFunction\n";

        cout << "rethrowing\n";
        throw except2();    // this will crash the program, as previous function (main) dont catch it
        
    } catch(const except2& e2) {
        cout << "this wont be printed\n";
    }
}

int main(int argc, char* argv[]) {
    someFunction();
}

/*output:

catched at someFunction
rethrowing
libc++abi.dylib: terminating with uncaught exception of type except2
Abort trap: 6
*/

3.cpp

#include <iostream>
using namespace std;

class except1 {};
class except2 {};

void someFunction() {
    try {
        throw except1();
    } catch(const except1& e) {
        cout << "catched at someFunction\n";

        cout << "rethrowing\n";

        try {
            throw except2();    // we will rethrow it and catch it in the same catch, it wond rewind the stack, it will be catched here
        } catch (const except2& e2) {
            cout << "catched except2 after rethrowing it\n";
        }

        cout << "this will be printed after continuing the above handling\n";
    } catch (const except2& e2) {
        cout << "this wont be printed, as it is handled above\n";
    }

    cout << "no problem at all , all errors have been handled, even if there was a rethrow\n";
}

int main(int argc, char* argv[]) {
    try {
        someFunction();
    } catch (const except2& e) {
        cout << "this wont be printed, as this exception has been handled in someFunction\n";
    }
}

/*output:

catched at someFunction
rethrowing
catched except2 after rethrowing it
this will be printed after continuing the above handling
no problem at all , all errors have been handled, even if there was a rethrow
*/