Re: C++11: Using noexcept

[Errol van de l'Isle <evandel cix co uk>]

On Sun, 2015-08-16 at 13:12 +0200, Murray Cumming wrote:
> I guess we could use noexcept on lots of our class methods -
> particularly simple boxed types such as Gdk::Rectangle, but maybe even
> anything that doesn't wrap a GError in an exception.
>
> Using noexcept seems to be more worthwhile than using throw() was,
> letting the compiler optimize more.
>
> It looks like adding noexcept doesn't break ABI. Does anyone know
> otherwise?
Doing some very simple tests and reading the documentation the noexcept
specifier does not form part of the mangled name very much like throw().
So I expect that this would break any ABI

int f(int a) noexcept
{
  return a;
}

and

int f(int a)
{
  return a;
}

Both produce exactly the same code using GCC and Clang. If they were
compiled together there will a compilation error with both being treated
as -

int f(int);

One thing to watch out for is that C code can throw an exception. One
way that this can be done is by declaring a function extern "C" during
"C++" compilation and throwing and exception there. There is probably
more ways to do this.