Enable C++.
Remove old work.
Clean C++ compile.
Localise variables in lbfgs.
Add report function.
Tidy docs.
Add report function.
Use std::array for iprint.
Split to separate files.
Split to separate files.
Split to separate files.
Remove pointer from n in lbfgs.
Remove print clutter.
Pass opts to main routine.
Use options and propagate consts.
Add to options.
Move some error checking to constructor.
Remove pointer from maxfev.
Remove pointer from nfev.
Forward options to mcsrch.