[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: C++ throw() clause
From: |
Bruno Haible |
Subject: |
Re: C++ throw() clause |
Date: |
Mon, 17 Aug 2020 01:13:57 +0200 |
User-agent: |
KMail/5.1.3 (Linux/4.4.0-186-generic; KDE/5.18.0; x86_64; ; ) |
Hi Florian,
> > clang (at least in version >= 4), in C++ mode, supports the 'throw
> > ()' declaration on functions, and uses it to optimize try/catch
> > statements at the caller site.
>
> I think throw() has been removed from C++20:
>
> <http://eel.is/c++draft/except.spec>
> <https://en.cppreference.com/w/cpp/language/except_spec>
>
> So it will soon break again.
Thanks for the heads-up. But g++ 10.2.0 still understands this
"removed" syntax:
==================== nothrow.cc ====================
extern int validate (int x) throw ();
extern void err (int e);
int foo (int x, int y)
{
try { validate (x); } catch (int e) { err (e); }
try { validate (y); } catch (int e) { err (e); }
return x + y;
}
====================================================
$ g++ -O2 -S -std=c++20 -Wall nothrow.cc
<no error, no warning>
And glibc/misc/sys/cdefs.h has not been updated yet. Is it certain
that GCC and the GCC compatible compilers (clang, icc, etc.) will
continue to support 'throw ()'?
Bruno