This only affects configurations where inline functions become regular,
non-weak symbols, leading to link conflicts. The extra definition was not
used anywhere.
The removed definition was probably less efficient. However the only
functional difference was that it returned false for the empty nonterminal,
i.e. "[]".
The duplicate definition works fine in environments where the inline
definition becomes a weak symbol in the object file, but if it gets
generated as a regular definition, the duplicate definition causes link
problems.
In most call sites the return value could easily be made const, which
gives both the reader and the compiler a bit more certainty about the code's
intentions. In theory this may help performance, but it's mainly for clarity.
The comments are based on reverse-engineering, and the unit tests are based
on the comments. It's possible that some of what's in there is not essential,
in which case, don't feel bad about changing it!
I left a third identical definition in place, though I updated it with my
changes to avoid creeping divergence, and noted the duplication in a comment.
It would be nice to get rid of this definition as well, but it'd introduce
headers from the main Moses tree into biconcor, which may be against policy.
