Re: We do not use C++ exceptions at Google

From:
"Bo Persson" <bop@gmb.dk>
Newsgroups:
comp.lang.c++.moderated
Date:
Mon, 19 Jan 2009 01:46:44 CST
Message-ID:
<6tgn3lFacu3iU1@mid.individual.net>
Maxim Yegorushkin wrote:

On Jan 15, 6:08 pm, Marsh Ray <marsh...@gmail.com> wrote:

On Jan 15, 10:30 am, Maxim Yegorushkin
<maxim.yegorush...@gmail.com> wrote:

Practically, I haven't seen a case
where cant-be-null property of references would make a difference
for
function arguments.


int a = 0, b = 1;

std::swap<int>(a, b); // Probably pretty darn efficient.


It as efficient as swap_c_style. See below.

swap_c_style(&a, &b);

The implementation of swap_c_style has to either check both args
for null, or produce undefined behavior over its domain of input
values.


No checks necessary, it should just dump a core file for your
examination.


This assumes that you have a hardware assisted check for null pointer
references. On other systems there will be an additional cost -
presumably the systems where you can afford this the least.

Bo Persson

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