Remove reachability_slicert::operator() definition to cpp file

This is a non-trivial implementation with external dependencies.
Upcoming changes will make it even more complex.

Author: tautschnig

src/goto-instrument/reachability_slicer.cpp

@@ -15,16 +15,37 @@ Author: Daniel Kroening, [email protected]
 
 #include "reachability_slicer.h"
 
+#include <util/exception_utils.h>
+
 #include <goto-programs/cfg.h>
 #include <goto-programs/remove_calls_no_body.h>
 #include <goto-programs/remove_skip.h>
 #include <goto-programs/remove_unreachable.h>
 
-#include <util/exception_utils.h>
+#include <analyses/is_threaded.h>
 
 #include "full_slicer_class.h"
 #include "reachability_slicer_class.h"
 
+void reachability_slicert::operator()(
+  goto_functionst &goto_functions,
+  const slicing_criteriont &criterion,
+  bool include_forward_reachability)
+{
+  cfg(goto_functions);
+  for(const auto &gf_entry : goto_functions.function_map)
+  {
+    forall_goto_program_instructions(i_it, gf_entry.second.body)
+      cfg[cfg.entry_map[i_it]].function_id = gf_entry.first;
+  }
+
+  is_threadedt is_threaded(goto_functions);
+  fixedpoint_to_assertions(is_threaded, criterion);
+  if(include_forward_reachability)
+    fixedpoint_from_assertions(is_threaded, criterion);
+  slice(goto_functions);
+}
+
 /// Get the set of nodes that correspond to the given criterion, or that can
 /// appear in concurrent execution. None of these should be sliced away so
 /// they are used as a basis for the search.

src/goto-instrument/reachability_slicer_class.h

@@ -12,11 +12,9 @@ Author: Daniel Kroening, [email protected]
 #ifndef CPROVER_GOTO_INSTRUMENT_REACHABILITY_SLICER_CLASS_H
 #define CPROVER_GOTO_INSTRUMENT_REACHABILITY_SLICER_CLASS_H
 
-#include <goto-programs/goto_functions.h>
-#include <goto-programs/cfg.h>
-
-#include <analyses/is_threaded.h>
+#include <goto-programs/goto_program.h>
 
+class goto_functionst;
 class slicing_criteriont;
 
 class reachability_slicert
@@ -25,21 +23,7 @@ class reachability_slicert
   void operator()(
     goto_functionst &goto_functions,
     const slicing_criteriont &criterion,
-    bool include_forward_reachability)
-  {
-    cfg(goto_functions);
-    for(const auto &gf_entry : goto_functions.function_map)
-    {
-      forall_goto_program_instructions(i_it, gf_entry.second.body)
-        cfg[cfg.entry_map[i_it]].function_id = gf_entry.first;
-    }
-
-    is_threadedt is_threaded(goto_functions);
-    fixedpoint_to_assertions(is_threaded, criterion);
-    if(include_forward_reachability)
-      fixedpoint_from_assertions(is_threaded, criterion);
-    slice(goto_functions);
-  }
+    bool include_forward_reachability);
 
 protected:
   struct slicer_entryt