GCC 11 Enables Co-Routines Support In C++20 Mode

[bug77]

coroutines have nothing to do with threads, they are syntactic sugar for callbacks(single threaded). they don't run concurrently and do not require synchronization, which has impact on reasoning and on execution

Actually, coroutines do run concurrently, they just don't run in parallel. But I'm just posting this for correctness' sake, I frequently mix those two up myself.

[kreijack]

Thanks!. Looks like it won't work on Linux at full power though, and most likely won't work at gcc-10 without some adoption.

True, I copied an example from the site but I didn't try to run. However my point was to highlight that the differences between the standard (which provides a very low level interface) and the library which will provide a more user (/developer) friendly interface.

[pal666]

I personally want to resolve an asynchronous hell.

networking ts could be merged into c++23

[pal666]

I'm kind of curious about what the motivation is for co-routines, though, since threads are better and fully supported.

coroutines have nothing to do with threads, they are syntactic sugar for callbacks(single threaded). they don't run concurrently and do not require synchronization, which has impact on reasoning and on execution

[dev_null]

it is possible, boost provides one. stackful and stackless both have their pros and cons, it's good to have both(or something combined, and there was an effort to combine them, but it wasn't successful yet)
microsoft was impatient because they need them for their api

I personally want to resolve an asynchronous hell. It's when you have a lot of lambdas/callbacks like described here but for C++ https://blog.hellojs.org/asynchronou...t-9b9ceb63c8e8
So I was extremely disappointed that the new coroutines just don't allow me to do this anyhow easily.

[dev_null]

The current implementation is the basic plumbing on which it is possible to build a library support. The intended use is not for the generic developer. You should look to a library like cppcoro https://github.com/lewissbaker/cppcoro which is a lot more user friendly :

using cppcoro;
generator<const std::uint64_t> fibonacci() {
std::uint64_t a = 0, b = 1;
while (true) {
co_yield b;
auto tmp = a;
a = b;
b += tmp;
}
}
void usage() {
for (auto i : fibonacci()) {
if (i > 1'000'000)
break;
std::cout << i << std::endl;
}
}

Thanks!. Looks like it won't work on Linux at full power though, and most likely won't work at gcc-10 without some adoption.

[pal666]

std::cout << i << std::endl;

https://www.youtube.com/watch?v=6WeEMlmrfOI

[pal666]

these new coroutines are extremely hard to use. Everyone who doesn’t believe welcome to try. I have no idea why it was not possible to provide stackfull coroutines python or java script style ??

it is possible, boost provides one. stackful and stackless both have their pros and cons, it's good to have both(or something combined, and there was an effort to combine them, but it wasn't successful yet)

However I know the current implementation in the standard was proposed by a guy from Microsoft.

microsoft was impatient because they need them for their api

[pal666]

I think C++ deserves a pat on the back for trying to catch up to Rust

you live in an alternative universe where rust had coroutines before c++?

[sindr]

On the other hand Go's version, goroutines, are spread by the runtime over any number of available threads.

Yep, see also Erlang and Project Loom's implementations.