Remove some tally-related C++/Fortran glue-code

This commit also removes some tally trigger special-case code for meshsurface current tallies. That code was broken and is also no longer needed.

include/openmc/tallies/tally.h

@@ -56,11 +56,8 @@ public:
   // We need to have quick access to some filters.  The following gives indices
   // for various filters that could be in the tally or C_NONE if they are not
   // present.
-  int energyin_filter_ {C_NONE};
   int energyout_filter_ {C_NONE};
   int delayedgroup_filter_ {C_NONE};
-  int surface_filter_ {C_NONE};
-  int mesh_filter_ {C_NONE};
 
   int deriv_ {C_NONE}; //!< Index of a TallyDerivative object for diff tallies.
 

include/openmc/tallies/trigger.h

@@ -0,0 +1,36 @@
+#ifndef OPENMC_TALLIES_TRIGGER_H
+#define OPENMC_TALLIES_TRIGGER_H
+
+#include <string>
+
+#include "pugixml.hpp"
+
+namespace openmc {
+
+//! Stops the simulation early if a desired tally uncertainty is reached.
+
+extern "C" struct Trigger
+{
+  int type;  //!< variance, std_dev, or rel_err
+  double threshold;  //!< uncertainty value below which trigger is satisfied
+  int score_index;  //!< index of the relevant score in the tally's arrays
+  double variance {0.};
+  double std_dev {0.};
+  double rel_err {0.};
+};
+
+//! Stops the simulation early if a desired k-effective uncertainty is reached.
+
+extern "C" struct KTrigger
+{
+  int type{0};
+  double threshold {0.};
+};
+
+//TODO: consider a different namespace
+namespace settings {
+  extern "C" KTrigger keff_trigger;
+}
+
+} // namespace openmc
+#endif // OPENMC_TALLIES_TRIGGER_H