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executors / futures

A proposal for a futures programming model for ISO C++
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Should `.then` be const qualified? #121

Open brycelelbach opened 6 years ago

brycelelbach commented 6 years ago

If so, future authors will probably have to make something (the executor, at least?) mutable.

RedBeard0531 commented 6 years ago

Futures will probably point-to rather than have an executor, so the pointer loophole to const already applies.

griwes commented 6 years ago

We guarantee that the shared state is synchronized; this would imply that the future objects themselves are synchronized, and I'm pretty sure we do not actually want to say that. (Think shared_ptr vs atomic.)

RedBeard0531 commented 6 years ago

Although at least for non-shared futures, they are a logically mutating operation so the answer is clearly no. Should the title be restricted just to SharedFuture?

jaredhoberock commented 6 years ago

Execution functions are const qualified and executors are intended to be passed around by value. The idea is that the executor acts as a sort of pointer or handle to an execution context or some other thing which actually mutates when work is created. So no, I don't think that .then() needs to be const-qualified on behalf of executors.