Re: C# vs. C++ (was Re: UNICODE conversion)

Hmm, maybe I should give an example in C++:

class CMyObject
{
     CFile m_file;
     CString m_filename; // filename opened into m_file

public:
    void foo()
    {
        try
        {
            m_file.Open(m_filename);

            // Cause divide-by-zero exception
            int i = 3 / 0;
        }

        m_file.Close();
    }

    void bar()
    {
        DeleteFile (m_filename);
    }
}

int main()
{
    CMyObject object;
    try
    {
        object.foo();
    }
    catch(...)
    {
         // handle divide by 0 error
    }

    object.bar();
}

So in the above C++ example, foo() throws an exception, and thus the
m_file.Close() is not executed. Then when bar() is called, it tries to
delete the file which was not closed and it fails.

Whereas, in C# using 'finally' this won't happen:

class CMyObject
{
     // declarations the same for sake of example;
    // I know there is no CFile or CString in .NET!
     CFile m_file;
     CString m_filename; // filename opened into m_file

public:
    void foo()
    {
        try
        {
            m_file.Open(m_filename);

            // Cause divide-by-zero exception
            int i = 3 / 0;
        }
        finally
        {
              // Close file in 'finally' to ensure it always executes before
foo() exits
              m_file.Close();
        }
    }

    void bar()
    {
        DeleteFile (m_filename);
    }
}

In C#, calling foo() and then bar() properly deletes the file because the
file has been closed prior to DeleteFile() being called.