On 9/24/14, 9:54 AM, Iain Buclaw via Digitalmars-d wrote:
On 24 September 2014 16:07, Andrei Alexandrescu via Digitalmars-d
<digitalmars-d@puremagic.com> wrote:
I wonder how difficult would be to create a wrapper class CppException for
everything derived from C++ std::exception. It would not save the exact
exception, but it would save its what() string and perhaps the
typeid().name(). A translator would create CppException objects from
std::exception objects and their derivatives.
How hard would that be? Please advise.
Thinking about it:
- Identifying a C++ exception, simple.
Noice.
- Identifying whether a D catch handler for a C++ exception object
matches, tricky - maybe. ABI of structs being a potential maintenance
burden - though you'd hope that they only change ABI once every two
years or so. Second, determining that the C++ object being thrown and
catch handler we are examining match might be awkward from D. That is
something that needs investigation.
Yah. I'm thinking of simplifying assumptions, e.g. all C++ exceptions
map to one single D type called CppException, and we can assume there's
always a D handler on top of the stack. All the CppException saves is a
copy of the what() message from the C++ exception.
However, for sure, the easiest thing that could be done *now* that
only needs a slight EH library tweak is using catch-all handlers to
recover from any language exception.
try {
SomeCxxFuncThatMayThrow();
}
catch {
// Recover, but without knowing what happened.
}
But I'd imagine you'd actually want information to come with your
caught exception, though. :)
Well even a catch like that would definitely be an improvement.
Andrei
