Re: How to throw standard exceptions ?

From:

peter koch <peter.koch.larsen@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Thu, 5 Feb 2009 15:01:19 -0800 (PST)

Message-ID:

<689832e6-30e3-48e6-acd0-4851d6c1fe5f@i24g2000prf.googlegroups.com>

On 5 Feb., 23:49, Timothy Madden <terminato...@gmail.com> wrote:

Hello

Almost every program I write starts by checking the number
of arguments and throws an exception if the syntax is not
right. And every time I get the same error: the exception
is not caught with its type, but with the last catch (...)
handler !

Here's an almost minimal example.
Can anyone please tell me what is wrong with my code ?

#include <stdexcept>
#include <iostream>
#include <cstdio>

using namespace std;

int main(int argc, const char *argv[])
     try
{
     if (argc != 3)
        throw
            new
                runtime_error
                    (
                        "Processes a Filemon log =

file and re-creates "

"the dire=

ctories and files listed\n"

                        "into the given path.\n"
                        "Syntax:\n"
                        "\tclassify LogFile.LOG \=

\root_path\n"

                        "\n"
                    );
     else
     {
        // Some processing
        // ...

        return EXIT_SUCCESS;
     }}

catch (const runtime_error &e)
{
     cerr << "Error:\n";
     cerr << e.what();
     cerr << endl;

     return EXIT_FAILURE;}

catch(const exception &e)
{
     cerr << "Error:\n";
     cerr << e.what();
     cerr << endl;

     return EXIT_FAILURE;}

catch (...)
{
     cerr << "General error.\n";

     return EXIT_FAILURE;

}

When I compile and run my program I get:

adrian@darkstar: g++ -o command command.cc
adrian@darkstar: ./command
General failure.

I have tried with Slackware Linux 2.6.14 gcc 4.2.4
and mingw on Win32, gcc 3 ...

You are throwing a pointer to a runtime_error, not a runtime_error.

/Peter