Polymorphic injectors, external currents, and diagnostics

src/include/injector_base.hxx

@@ -0,0 +1,29 @@
+#pragma once
+
+template <typename MPARTICLES, typename MFIELDS_STATE>
+struct InjectorBase
+{
+  using Mparticles = MPARTICLES;
+  using MfieldsState = MFIELDS_STATE;
+
+  virtual void inject(Mparticles& mprts, MfieldsState& mflds) = 0;
+};
+
+template <typename MPARTICLES, typename MFIELDS_STATE>
+struct InjectFromLambda : InjectorBase<MPARTICLES, MFIELDS_STATE>
+{
+  using Mparticles = MPARTICLES;
+  using MfieldsState = MFIELDS_STATE;
+
+  InjectFromLambda(std::function<void(Mparticles&, MfieldsState&)> lambda)
+    : lambda{lambda}
+  {}
+
+  void inject(Mparticles& mprts, MfieldsState& mflds) override
+  {
+    return lambda(mprts, mflds);
+  }
+
+private:
+  std::function<void(Mparticles&, MfieldsState&)> lambda;
+};