On 10/27/2016 08:34 AM, Jonathan Wakely wrote:
On 27 October 2016 at 15:30, Edward Diener
<eldlistmailingz@xxxxxxxxxxxxxx> wrote:
On 10/27/2016 10:00 AM, Jonathan Wakely wrote:
On 27 October 2016 at 14:52, Edward Diener wrote:
It sounds like you are also saying that there is no way to catch the old
type, even if I wanted to, since the header file declaration has the
decorated attribute.
No, the attribute is only present conditionally, see
https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html
If you compile with _GLIBCXX_USE_CXX11_ABI defined to zero then you
get the declaration of the old type (and the old COW std::string, and
the old std::list with O(n) size()).
Thanks ! IMO clearly you should be throwing the std::ios_base::failure which
corresponds to the _GLIBCXX_USE_CXX11_ABI macro setting being used.
The exception is thrown from code inside libstdc++.so, which is
already compiled and can't be affected by a macro defined when you
#include <iostream>.
I wonder if a trick along the lines of ios_base::Init could do it,
say ios_base::FailureInit. The class ctor would set a value that
the library checked before throwing an ios_base::failure to decide
which of the two types to throw.
It would have to be a program-wide setting (i.e., a program would
have to #define _GLIBCXX_USE_CXX11_ABI to the same value in every
translation unit).
Martin
