mention finalization when user tries to use System API from Builder
Closes #117 (closed).
I implemented the fix proposed by @anton-akhmerov. It is now up to @cwg and @anton-akhmerov whether to merge this, or to close #117 (closed) as wontfix
Closes #117 (closed).
I implemented the fix proposed by @anton-akhmerov. It is now up to @cwg and @anton-akhmerov whether to merge this, or to close #117 (closed) as wontfix