Message-ID:	<375704F3.B04865EA@pacificnet.net>
Date:	Thu, 03 Jun 1999 15:42:59 -0700
From:	Ralph Gesler <rgesler AT pacificnet DOT net>
X-Mailer:	Mozilla 4.5 [en] (Win95; U)
X-Accept-Language:	en,ja
MIME-Version:	1.0
To:	djgpp AT delorie DOT com
Subject:	Re: new's return on fail
References:	<3754FA2C DOT 54A26758 AT softhome DOT net>
Reply-To:	djgpp AT delorie DOT com

Chris Mears wrote:
> 
> Hi all...
> 
> What does new return if it fails?  I've heard that the standard requires
> that it throw an exception, but also I've heard that it returns NULL
> (like malloc).  I did a test, and it did neither, preferring to exit the
> program.  So, how do I capture this and use it for the greater good
> (rather than just exiting the program)?
> 
> Chris

Looking at a draft version of the C++ spec and Stroustrup I think the
answer is  "depends". The single parameter version of new, size_t, will
throw an exception bad_alloc if allocation fails. Other nothrow versions
return 0 if allocation fails. An example from Stroustrup:

	void f()
	{
		int*p = new int[100000}; //may throw bad_alloc
		if(int*q = new(nothrow) int[100000]);
{                                       //will not throw exception
		
		}
		else {
  			// allocation failed
		}
}

Ralph

- Raw text -