MM Uses Plugins (Don't Merge Yet)

CMakeLists.txt

@@ -158,7 +158,7 @@ if(BUILD_PYBIND11_BINDINGS AND BUILD_TESTING)
         SOURCES
             "${_pluginplay_examples_dir}/classical_force.cpp"
             "${_pluginplay_examples_dir}/coulombs_law.cpp"
-            "${_pluginplay_examples_dir}/load_modules.cpp"
+            "${_pluginplay_examples_dir}/pluginplay_examples.cpp"
             "${_pluginplay_examples_dir}/screened_coulombs_law.cpp"
             "${_pluginplay_examples_dir}/templated_coulombs_law.cpp"
         TYPE STATIC

cxx/include/pluginplay/module/module_class.hpp

@@ -16,6 +16,7 @@
 
 #pragma once
 #include "pluginplay/types.hpp"
+#include <memory>
 #include <pluginplay/fields/fields.hpp>
 #include <pluginplay/property_type/python_only_property_type.hpp>
 #include <pluginplay/utility/uuid.hpp>
@@ -49,8 +50,13 @@ struct ModuleManagerPIMPL;
  *  and is needed by the pluginplay framework to correctly use the module. This
  * state is not accessible (nor relevant) once the module is running. For the
  * most part users will only be interested in algorithm state.
+ *
+ *  Modules stored in a ModuleManager, ModuleMap, or SubmoduleRequest are owned
+ *  by shared_ptrs. Module derives from enable_shared_from_this so the Python
+ *  bindings can hand out shared ownership of those modules; a copy of a
+ *  Module is still an independent module.
  */
-class Module {
+class Module : public std::enable_shared_from_this<Module> {
 public:
     /// Type of a pointer to a PIMPL
     using pimpl_ptr = std::unique_ptr<detail_::ModulePIMPL>;
@@ -745,6 +751,9 @@ class Module {
     bool operator!=(const Module& rhs) const { return !((*this) == rhs); }
 
 private:
+    /// Lets the ModuleManager attach its runtime and caches to the module
+    friend struct detail_::ModuleManagerPIMPL;
+
     /** @brief Unlocks a locked module
      *
      *  There are very select circumstances when we need to unlock a locked

cxx/include/pluginplay/module_manager/module_manager.hpp

@@ -17,3 +17,4 @@
 #pragma once
 #include <pluginplay/module_manager/module_manager_class.hpp>
 #include <pluginplay/module_manager/module_map.hpp>
+#include <pluginplay/module_manager/qualified_key.hpp>