Re: No-fail guarantee for assignment to equally sized std::vector?

From:

Carl Barron <cbarron413@adelphia.net>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 11 Apr 2007 17:47:24 CST

Message-ID:

<110420071713172152%cbarron413@adelphia.net>

In article <87lkgyc1o9.fsf@grogan.peloton>, David Abrahams
<dave@boost-consulting.com> wrote:

on Tue Apr 10 2007, Carl Barron <cbarron413-AT-adelphia.net> wrote:

In article <461C066B.250ECB09@this.is.invalid>, Niels Dekker - no
return address <noreply@this.is.invalid> wrote:

Suppose you have two vectors of a built-in type, whose sizes are equal:

   std::vector<double>::size_type n = 32767;
   std::vector<double> v1(n);
   std::vector<double> v2(n);

Is the assignment of one such vector to the other guaranteed to be
successful? Or is there a serious chance that this assignment will
throw a bad_alloc?

   v1 = v2; // No-fail guarantee?

No but if an exception occurs then the assignment has no effect.

I didn't remember specifying that, so I went back and looked at the
standard. Indeed, AFAICT, it doesn't say that. Or is there some
text I've forgotten that supports your assertion?

   Faulty memory:) I stand corrected.

any way the answer to the original question is still no.

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