Re: Console application termination following exception thrown in constructor (VS 2005)

From:

"Tom Widmer [VC++ MVP]" <tom_usenet@hotmail.com>

Newsgroups:

microsoft.public.vc.language

Date:

Mon, 15 Jan 2007 12:42:26 +0000

Message-ID:

<OeEUeKKOHHA.4604@TK2MSFTNGP06.phx.gbl>

Paul wrote:

The code looks like the following:

-----------------------
C::C(const char* ss...)
try
    : ..., settings(ss) /*third-party class that can throw E*/, ...
{
    ...
}
catch (const E& e) {
    std::cerr << e.what();

The compiler inserts here:
throw;

}
;

-----------------------

(First, a minor point: in my experience whenever constructs similar to above
are used - when "try" appears outside the main function body not necessarily
within a constructor (can be something along these lines: int main() try
{...} catch (...) {...}) - unless they are fairly simple, code will not
compile without the semicolon (;) after the closing curly brace.)

I understand that when a constructor of a class throws an exception, that
class will not be constructed even if the exception is caught as in the
above code - and I do not count on the object creation.

The exception is automatically rethrown at the end of the catch block
for a function try block of a constructor or destructor.

However, I could not

find a way to exit the application gracefully in this case.

Just catch the exception (assuming the object being constructed isn't
global).

The above works

to the extent that the error (exception) is reported properly but this is
followed by

-----------------------
This application has requested the Runtime to terminate it in an unusual
way.
Please contact the application's support team for more information.

-----------------------

and then the dialogue box "Please tell Microsoft about this problem."
appears.

When the object construction is put within a try-block

try { C c(...); } catch (...) { std::cerr << "Error.\n"; }

the application just silently exits.

Presumably with e.what() and "Error.\n" output, right?

Is there a way to display just the error message when "settings(ss)" throws
an exception without the "This application has requested..."? (I am aware of
how to disable "Please tell Microsoft..." for an application via an API but
it is "The application has requested..." that I do not know how to deal
with.)

It's up to you how you handle the exception, but if you let an exception
propogate up through main as you do in your first version (where
presumably the object creation isn't in a try block) I think that dialog
is unavoidable.

Tom