Thread: Exceptions and constructors

I would like to convert this code to use exceptions (let's assume that in practice, this code would be more complex.). The question is, how/where would I do it? Do I catch the exception in the constructor, main(), or in one of the other functions? Where do I define the exception class? Would it be part of CTest, or another file altogether? Basically, I'd like to catch exceptions and exit execution cleanly - allowing any cleanup to be done. Any words of wisdom?

Class definition:

Code:

//File: Test.h
#include <string>
#include <iostream>
using namespace std;

class CTest  
{
public:
	string m_Welcome;
	CTest(string str_welcome);
	void SetWelcomeString(string welcome_str);
	int DoSomething(void);
};

Class implementation:

Code:

//File: Test.cpp
#include "Test.h"

CTest::CTest(string welcome_str)
{
    CTest::SetWelcomeString(welcome_str);
	if(CTest::DoSomething())
    {
        cerr << "Error!" << endl;
        exit(1);
    }
}

void CTest::SetWelcomeString(string welcome_str)
{
    m_Welcome = welcome_str;
}

int CTest::DoSomething(void)
{
    //returns 0 on success, 1 on failure
    if(m_Welcome.length())
    { 
        cout << m_Welcome << endl;
        return(0);
    }
    //else
    return(1);
}

Main:

Code:

//File: ExceptTest.cpp
#include "Test.h"

int main()
{
	CTest testing("Hello, World!");
	return 0;
}

Catch the exception at the point in the code where something can be DONE about the failure. Catching an exception is pointless if you can do nothing to resolve it. Therefore, where and how you catch exceptions depends on the type of exception you are trying to catch, who is throwing it, and what caused it.