Robert, for someone who has only vague knowledge of signal
stuff (me), can you explain why exactly this design was
necessary? (mixing in global variable and wrapper function
which returns its restricted version) Is the desire to separate
protection attributes the only motivation or there are some
other concerns?
No this is the only reason. Usually it is the common case that
you only want the "owner" of the signal to emit it. Without the
mixin, this would require the following boilerplate for every
single signal:
ref RestrictedSignal!(SomeTemplate!int) mysig() { return
_mysig;}
private Signal!(SomeTemplate!int) _mysig;
which is a bit tedious.
I am currently considering the suggestions of Jacob Carlborg:
- using an enum for the protections
- provide an additional template mixin wrapper for another minor
reduction of boilerplate.
Signal slot frameworks in C++ usually either only allow the owner
to emit the signal (Qt) or you are required to write some wrapper
functions for restrictions on the public API (e.g. boost signal).
Best regards,
Robert
