What happened to our mutable lambdas?

[aaronalbers]

This simple piece of code will no longer compile (tested with 1.5.1).

#include <iostream>

#include <stlab/concurrency/default_executor.hpp>
#include <stlab/concurrency/future.hpp>

int main() {
   auto func = [i = int{0}]() mutable {
      i++;
   };
   
   stlab::async(stlab::default_executor, [func = std::move(func)]() mutable {
      func();
      
      stlab::async(stlab::default_executor, [func = std::move(func)]() mutable {
         func();
      }).detach();
      
   }).detach();
   
   return 0;
}

When I tried to upgrade to the latest version of stlab I was surprised to find that all of my wrapper functions would no longer compile. I have periodic task wrappers that function in principle like the above code.

IMHO the fallout from #260 was much larger than it needed to be as we are still trying to get back functionality like with #287

For the time being I am stuck at version 1.4.1

[sean-parent]

I believe the fix for #260 removed too many mutables

[FelixPetriconi]

I started looking into this

[aaronalbers]

For my use cases I was able to get everything compiled by adding mutable on the following lines in future.hpp:

1636
536
1800

[FelixPetriconi]

At the moment I am adding tests to cover all possibilities. So far only 1636 was needed for me. But I am not done.