Actions can not use concepts / constrained auto parameters

[gotnone]

Expected Behavior

I expected to be able to write actions that can take constrained auto parameters

Actual Behavior

State machine fails to compile

Steps to Reproduce the Problem

1. Create a concept
2. Add the concept as a constrained auto parameter to an action lambda
3. Create an instance of a type satisfying the concept
4. pass the instance of the type to the sm constructor
5. Attempt to compile
6. See template errors and failure to compile

See the "hello world" example modified to use a concept in the send_fin action:
https://godbolt.org/z/ErxT5YqM9

A version that tries to call a wrapped free function with a constrained auto type:
https://godbolt.org/z/GThY848jo

Specifications

• Version: 0bdc4f5
• Platform: Mingw64 and Linux
• Subsystem:

[Schoppenglas]

The SML lib targets C++14.