introducing GimmickGuard (to avoid manual memory freeing) (#263)

Co-authored-by: Zach D'Aquino <[email protected]>

Author: slayoo

src/aero_data.hpp

@@ -34,9 +34,9 @@ struct AeroData {
     {
         if (!InputGimmick::unique_keys(json))
             throw std::runtime_error("Species names must be unique");
-        gimmick_ptr() = std::make_unique<InputGimmick>(json);
+
+        GimmickGuard<InputGimmick> guard(json);
         f_aero_data_from_json(this->ptr.f_arg());
-        gimmick_ptr().reset(); // TODO #117: guard
     }
 
     static auto spec_by_name(const AeroData &self, const std::string &name) {

src/aero_dist.hpp

@@ -51,9 +51,9 @@ struct AeroDist {
     {
         if (!InputGimmick::unique_keys(json))
             throw std::runtime_error("Mode names must be unique");
-        gimmick_ptr() = std::make_unique<InputGimmick>(json, "", "mode_name", 1);
+        
+        GimmickGuard<InputGimmick> guard(json, "", "mode_name", 1);
         f_aero_dist_from_json(ptr.f_arg_non_const(), aero_data->ptr.f_arg_non_const());
-        gimmick_ptr().reset();
     }
 
     AeroDist() :

src/aero_mode.hpp

@@ -130,9 +130,9 @@ struct AeroMode {
     {
         if (json.size() != 1)
             throw std::runtime_error("Single element expected");
-        gimmick_ptr() = std::make_unique<InputGimmick>(json, "", "mode_name");
+
+        GimmickGuard<InputGimmick> guard(json, "", "mode_name");
         f_aero_mode_from_json(ptr.f_arg_non_const(), aero_data.ptr.f_arg_non_const());
-        gimmick_ptr().reset();
     }
 
     static auto get_num_conc(const AeroMode &self){

src/env_state.hpp

@@ -29,9 +29,8 @@ struct EnvState {
     EnvState(const nlohmann::json &json) :
         ptr(f_env_state_ctor, f_env_state_dtor)
     {
-        gimmick_ptr() = std::make_unique<InputGimmick>(json); // TODO #117: guard
+        GimmickGuard<InputGimmick> guard(json);
         f_env_state_from_json(this->ptr.f_arg());
-        gimmick_ptr().reset();
     }
 
     static void set_temperature(const EnvState &self, double &temperature) {

src/gas_data.hpp

@@ -34,9 +34,8 @@ struct GasData {
                 nlohmann::json::array()
             }}));
 
-        gimmick_ptr() = std::make_unique<InputGimmick>(json_array);
+        GimmickGuard<InputGimmick> guard(json_array);
         f_gas_data_from_json(this->ptr.f_arg());
-        gimmick_ptr().reset(); // TODO #117: guard
     }
 
     static auto __str__(const GasData &self) {

src/gas_state.hpp

@@ -59,12 +59,11 @@ struct GasState {
     }
 
     static auto __str__(const GasState &self) {
-        gimmick_ptr() = std::make_unique<OutputGimmick>(); // TODO #117: guard
+        GimmickGuard<OutputGimmick> guard;
 
         f_gas_state_to_json(self.ptr.f_arg());
         auto str = gimmick_ptr()->str();
 
-        gimmick_ptr().reset(); // TODO #117: guard
         return str;
     }
 
@@ -118,10 +117,8 @@ struct GasState {
     }
 
     static void set_mix_rats(const GasState &self, const nlohmann::json &json) {
-
-        gimmick_ptr() = std::make_unique<InputGimmick>(json);
+        GimmickGuard<InputGimmick> guard(json);
         f_gas_state_from_json(self.ptr.f_arg(),
              self.gas_data->ptr.f_arg());
-        gimmick_ptr().reset(); // TODO #117: guard
     }
 };

src/gimmicks.hpp

@@ -308,3 +308,35 @@ struct OutputGimmick: Gimmick {
 
 std::unique_ptr<Gimmick> &gimmick_ptr();
 
+template <typename T>
+struct GimmickGuard {
+    GimmickGuard() {
+        gimmick_ptr() = std::make_unique<T>();
+    }   
+
+    GimmickGuard(const nlohmann::json & json) {
+        gimmick_ptr() = std::make_unique<T>(json);
+    }
+
+    GimmickGuard(
+        const nlohmann::json & json,
+        const std::string key_cond,
+        const std::string key_name
+    ) {
+        gimmick_ptr() = std::make_unique<T>(json, key_cond, key_name);
+    }
+
+    GimmickGuard(
+        const nlohmann::json & json,
+        const std::string key_cond,
+        const std::string key_name,
+        const int max_zoom_level
+    ) {
+        gimmick_ptr() = std::make_unique<T>(json, key_cond, key_name, max_zoom_level);
+    }
+
+    ~GimmickGuard() {
+        gimmick_ptr().reset();
+    }   
+};
+

src/run_part_opt.hpp

@@ -46,9 +46,8 @@ struct RunPartOpt {
             if (json_copy.find(key) == json_copy.end())
                 json_copy[key] = 0;
 
-        gimmick_ptr() = std::make_unique<InputGimmick>(json_copy); // TODO #117: guard
+        GimmickGuard<InputGimmick> guard(json_copy);
         f_run_part_opt_from_json(this->ptr.f_arg());
-        gimmick_ptr().reset();
     }
 
     static auto t_max(const RunPartOpt &self){

src/scenario.hpp

@@ -95,13 +95,12 @@ struct Scenario {
         ptr(f_scenario_ctor, f_scenario_dtor),
         json(json)
     {
-        gimmick_ptr() = std::make_unique<InputGimmick>(json, "dist", "mode_name"); // TODO #117: guard
+        GimmickGuard<InputGimmick> guard(json, "dist", "mode_name");
         f_scenario_from_json(
             gas_data.ptr.f_arg(),
             aero_data.ptr.f_arg(),
             this->ptr.f_arg()
         );
-        gimmick_ptr().reset();
     }
 
     static auto __str__(const Scenario &self) {