Adding clone method

NAMESPACE

@@ -102,6 +102,7 @@ export(add_virus_n)
 export(agents_from_edgelist)
 export(agents_smallworld)
 export(change_state)
+export(clone_model)
 export(get_agents)
 export(get_agents_data_ncols)
 export(get_agents_states)

R/cpp11.R

@@ -260,6 +260,10 @@ initial_states_cpp <- function(model, proportions) {
   .Call(`_epiworldR_initial_states_cpp`, model, proportions)
 }
 
+clone_model_cpp <- function(model) {
+  .Call(`_epiworldR_clone_model_cpp`, model)
+}
+
 tool_cpp <- function(name, susceptibility_reduction, transmission_reduction, recovery_enhancer, death_reduction) {
   .Call(`_epiworldR_tool_cpp`, name, susceptibility_reduction, transmission_reduction, recovery_enhancer, death_reduction)
 }

R/model-methods.R

@@ -365,3 +365,18 @@ initial_states <- function(model, proportions) {
 
 }
 
+#' @rdname epiworld-methods
+#' @export
+#' @details `epiworld_model` objects are pointers to an underlying C++ class
+#' in `epiworld`. To generate a copy of a model, use `clone_model`, otherwise,
+#' the assignment operator will only copy the pointer.
+#' @return
+#' - `clone_model` returns a copy of the model.
+clone_model <- function(model) {
+  stopifnot_model(model)
+  structure(
+    clone_model_cpp(model),
+    class = class(model)
+  )
+}
+

src/cpp11.cpp

@@ -460,6 +460,13 @@ extern "C" SEXP _epiworldR_initial_states_cpp(SEXP model, SEXP proportions) {
     return cpp11::as_sexp(initial_states_cpp(cpp11::as_cpp<cpp11::decay_t<SEXP>>(model), cpp11::as_cpp<cpp11::decay_t<cpp11::doubles>>(proportions)));
   END_CPP11
 }
+// model.cpp
+SEXP clone_model_cpp(const SEXP & model);
+extern "C" SEXP _epiworldR_clone_model_cpp(SEXP model) {
+  BEGIN_CPP11
+    return cpp11::as_sexp(clone_model_cpp(cpp11::as_cpp<cpp11::decay_t<const SEXP &>>(model)));
+  END_CPP11
+}
 // tool.cpp
 SEXP tool_cpp(std::string name, double susceptibility_reduction, double transmission_reduction, double recovery_enhancer, double death_reduction);
 extern "C" SEXP _epiworldR_tool_cpp(SEXP name, SEXP susceptibility_reduction, SEXP transmission_reduction, SEXP recovery_enhancer, SEXP death_reduction) {
@@ -787,6 +794,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_epiworldR_agents_from_edgelist_cpp",             (DL_FUNC) &_epiworldR_agents_from_edgelist_cpp,              5},
     {"_epiworldR_agents_smallworld_cpp",                (DL_FUNC) &_epiworldR_agents_smallworld_cpp,                 5},
     {"_epiworldR_change_state_cpp",                     (DL_FUNC) &_epiworldR_change_state_cpp,                      4},
+    {"_epiworldR_clone_model_cpp",                      (DL_FUNC) &_epiworldR_clone_model_cpp,                       1},
     {"_epiworldR_get_agent_cpp",                        (DL_FUNC) &_epiworldR_get_agent_cpp,                         2},
     {"_epiworldR_get_agents_cpp",                       (DL_FUNC) &_epiworldR_get_agents_cpp,                        1},
     {"_epiworldR_get_agents_data_ncols_cpp",            (DL_FUNC) &_epiworldR_get_agents_data_ncols_cpp,             1},

src/model.cpp

@@ -315,3 +315,16 @@ SEXP initial_states_cpp(SEXP model, cpp11::doubles proportions) {
   return model;
 
 }
+
+// Function for cloning a model
+[[cpp11::register]]
+SEXP clone_model_cpp(const SEXP & model) {
+
+  external_pointer<const Model<>> modelptr(model);
+
+  return external_pointer<Model<>>(
+    new Model<>(*modelptr)
+  );
+
+}
+