Function assign_expr

boost/optional/optional.hpp:317–322

#ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
    template<class Expr>
    void assign_expr ( Expr const& expr, Expr const* tag )
      {
        if (is_initialized())
             assign_expr_to_initialized(expr,tag);
        else construct(expr,tag);
      }
#endif

  public :