Question regarding implementation of exceptions in cpp2.

[AvangardAA]

Greetings!
Currently wondering where its possible to find a docs or examples on semantics of try {} catch {} and throw in cpp2. I've seen issues #111 and #361 but there is no explicit answer on how to define a try-catch block or how to catch what's thrown by 'throws' word i've seen in listed issues.
Thanks in advance.

[DyXel]

Exceptions haven't yet been implemented in Cpp2/cppfront. AFAIK, there's plan for them in the future.

[MatthieuHernandez]

If I import a cpp1 library into my cpp2 project, exceptions from my library just result in abort() and I can't retrieve the exception message.
Really annoying 😩

[JohelEGP]

Since you're writing a library, you don't want to replace the default handler.
IIRC the way to have a contract use a specific handler is
by passing it as the first template argument,
e.g. assert<my_handler>(a && b);.

[MatthieuHernandez]

void test() {
    throw std::runtime_error("message to retrieve");
}

main:() -> int = {
    test();
    return 0;
}

I can't figure out what to write in the main function to get my error message displayed at runtime.
(Assuming that the test method comes from an imported cpp1 library.)

[JohelEGP]

Sounds like you need try/catch syntax in Cpp2, which isn't implemented yet.

[MatthieuHernandez]

Ah, I have the impression that this is a CMake and compiler option related problem more than a cpp2 problem. Sorry for the inconvenience and thanks for the help. I'll keep working on a solution on my own.

[MatthieuHernandez]

I've found the perfect simple solution, just encapsulate all the code in a try catch 😊

cpp2_main:() -> int = {
    // My entire cpp2 code.
}

int main() {
    try {  // CPP2 workaround: Try catch not yet supported.
        return cpp2_main();
    } catch (const std::exception& e) {
        std::cerr << "Caught exception: " << e.what() << std::endl;
    }
    return 0;
}