A remark from @levo-str : in colvargrid derived classes, there are a lot of forwarded functions like this:

std::ostream &colvar_grid_scalar::write_restart(std::ostream &os)
{
  return colvar_grid<cvm::real>::write_restart(os);
}

Many of them are not used and can be removed entirely. Others can be just grabbed from the base class with using (C++11 and later). This would shave a bunch of code from colvargrid.cpp.

Specifically, the colvar_grid_scalar class would contain:

using  colvar_grid<cvm::real>::write_restart;

Edit: there are unused features in colvargrid_scalar (samples grid), and a lot of redundancy between colvargrid_count and colvargrid_scalar.

Action plan:

• remove samples member from colvargrid_scalar
• replace explicit forwards with using statements in declaration
• merge colvargrid_count into a template class colvargrid_scalar with integer or real type