take ownership of underlying process

corsika/detail/framework/process/IntLengthModifyingProcess.inl

@@ -17,9 +17,9 @@ namespace corsika {
 
   template <class TUnderlyingProcess>
   inline IntLengthModifyingProcess<TUnderlyingProcess>::IntLengthModifyingProcess(
-      TUnderlyingProcess& process,
+      TUnderlyingProcess&& process,
       std::function<IntLengthModifyingProcess::functor_signature> modifier)
-      : process_{process}
+      : process_{std::move(process)}
       , modifier_{std::move(modifier)} {}
 
   template <class TUnderlyingProcess>
@@ -40,4 +40,15 @@ namespace corsika {
     return modifier_(original, pid, energy);
   }
 
+  template <class TUnderlyingProcess>
+  inline TUnderlyingProcess const&
+  IntLengthModifyingProcess<TUnderlyingProcess>::getProcess() const {
+    return process_;
+  }
+
+  template <class TUnderlyingProcess>
+  inline TUnderlyingProcess& IntLengthModifyingProcess<TUnderlyingProcess>::getProcess() {
+    return process_;
+  }
+
 } // namespace corsika

corsika/framework/process/IntLengthModifyingProcess.hpp

@@ -35,7 +35,7 @@ namespace corsika {
     //! energy
     using functor_signature = GrammageType(GrammageType, corsika::Code, HEPEnergyType);
 
-    IntLengthModifyingProcess(TUnderlyingProcess& process,
+    IntLengthModifyingProcess(TUnderlyingProcess&& process,
                               std::function<functor_signature> modifier);
 
     //! wrapper around internal process doInteraction
@@ -46,8 +46,11 @@ namespace corsika {
     template <typename TParticle>
     GrammageType getInteractionLength(TParticle const& particle);
 
+    TUnderlyingProcess const& getProcess() const;
+    TUnderlyingProcess& getProcess();
+
   private:
-    TUnderlyingProcess& process_;
+    TUnderlyingProcess process_;
     std::function<functor_signature> const modifier_{non_modifying_functor};
   };
 

tests/framework/testIntLengthModifyingProcess.cpp

@@ -14,6 +14,8 @@
 using namespace corsika;
 
 struct DummyProcess {
+  int id{0};
+
   template <typename TParticle>
   GrammageType getInteractionLength(TParticle const&) {
     return 100_g / 1_cm / 1_cm;
@@ -23,6 +25,13 @@ struct DummyProcess {
   void doInteraction(TArgument& arg) {
     arg = 3;
   }
+
+  DummyProcess() = default;
+  DummyProcess(DummyProcess&&) = default;
+
+  // prevent copying
+  DummyProcess(DummyProcess const&) = delete;
+  DummyProcess& operator=(DummyProcess const&) = delete;
 };
 
 struct DummyParticle {
@@ -33,12 +42,14 @@ struct DummyParticle {
 
 TEST_CASE("IntLengthModifyingProcess", "[process]") {
   DummyProcess u;
+  u.id = 38;
 
   auto const modifier = [](GrammageType orig, Code, HEPEnergyType) -> GrammageType {
     return orig * 2;
   };
 
-  IntLengthModifyingProcess mod{u, modifier};
+  IntLengthModifyingProcess mod{std::move(u), modifier};
+  REQUIRE(std::is_same_v<decltype(mod), IntLengthModifyingProcess<DummyProcess>>);
 
   SECTION("getInteractionLength") {
     DummyParticle const p;
@@ -50,4 +61,13 @@ TEST_CASE("IntLengthModifyingProcess", "[process]") {
     mod.doInteraction(k);
     REQUIRE(k == 3);
   }
+
+  SECTION("getProcess") {
+    DummyProcess& uRef = mod.getProcess();
+    REQUIRE(uRef.id == 38);
+
+    decltype(mod) const& modConstRef = mod;
+    DummyProcess const& uConstRef = modConstRef.getProcess();
+    REQUIRE(uConstRef.id == 38);
+  }
 }