Re: [Boost-users] [coroutine] new versions

5 Oct 2012


      Am 05.10.2012 20:10, schrieb Nat Linden:
...
On Fri, Oct 5, 2012 at 11:22 AM, Oliver Kowalke  wrote:
...
Version 1) requires that coroutine-fn has only one argument ==
coroutine<>::self_t. Other arguments are accessed via
coroutine<>::self_t::get< int >() and results via coroutine<>::get().
interface provides input/output iterators.
I'm not sure this is an improvement over having yield() return a
tuple.
yield() returns a reference to coroutine<>::self_t.
I decided to remove the parameters from the coroutine-fn signature and
let the user access them via self_t::get< N >(). Then it should be clearer
when and where the values are updated/available after a yield/resume
cycle.
...
...
Version 2) requires that coroutine-fn has only one argument too ==
coroutine<> with inverted signature.
The signature inversion thing makes me uneasy. Although I don't yet
have a definite case in mind, I worry that would make it difficult to
synthesize a coroutine as a helper object in generic code that needs
to deal with arbitrary signatures.
coroutine<>::caller_t is a typedef of the coroutine type expected/passed to
coroutine-fn.

typedef coroutine< int( int, int> > coro_t;
int fn( coro_t::caller_t & c) {
     int x = c.get().get< 0 >();
     int y = c.get().get< 1 >();
     c( x +y);
     ...
}
coro_t coro( fn);
int res = c( 3, 7).get();

regards,
Oliver