...

asibfm700/asibfm700_configfile.h

@@ -249,6 +249,31 @@ public:
         return res;
     }
 
+    template <typename T>
+    bool update(std::string_view key, const T& value)
+    {
+        auto it = _configDB.find(key);
+        if (it == _configDB.end()) {
+            return false;
+        }
+
+        bool ok;
+        std::visit(
+            [&value, &ok](auto& val) {
+                using v_t = std::decay_t<decltype(val)>;
+
+                if constexpr (std::convertible_to<T, v_t>) {
+                    val = static_cast<v_t>(value);
+                    ok = true;
+                } else {
+                    ok = false;
+                }
+            },
+            it->second);
+
+        return ok;
+    }
+
 protected:
     std::unordered_map<std::string_view, variant_from_tuple_t<deduce_val_types_t<DESCR_T>>> _configDB;
 
@@ -453,11 +478,12 @@ class Asibfm700MountConfig : protected ConfigHolder<decltype(Asibfm700MountConfi
     using base_t = ConfigHolder<decltype(Asibfm700MountConfigDefaults)>;
 
 public:
+    using base_t::update;
     using base_t::value;
 
     Asibfm700MountConfig() : base_t(Asibfm700MountConfigDefaults)
     {
-        update();
+        updateAll();
     }
 
     ~Asibfm700MountConfig() = default;
@@ -481,7 +507,7 @@ public:
 
                 ec = base_t::parse(buffer, deserializer);
                 if (!ec) {
-                    update();
+                    updateAll();
                 }
             } catch (std::ios_base::failure const& ex) {
                 ec = ex.code();
@@ -497,6 +523,17 @@ public:
         return ec;
     }
 
+    template <typename T>
+    bool update(std::string_view key, const T& value)
+    {
+        bool ok = base_t::update(key, value);
+        if (ok) {
+            updateAll();
+        }
+
+        return ok;
+    }
+
     std::chrono::milliseconds hardwarePollingPeriod{};
 
     mcc::MccAngle siteLatitude{};
@@ -517,7 +554,7 @@ public:
     Asibfm700PCM::pcm_data_t pcmData{};
 
 protected:
-    void update()
+    void updateAll()
     {
         hardwarePollingPeriod = std::get<decltype(hardwarePollingPeriod)>(this->_configDB["hardwarePollingPeriod"]);
 

asibfm700/tests/cfg_test.cpp

@@ -62,6 +62,11 @@ int main()
 
     std::cout << "refr w: " << acfg.refractWavelength << "\n";
 
+    acfg.update("refractWavelength", 0.3);
+
+    auto e = acfg.value<double>("refractWavelength");
+    std::cout << "refr w: " << e.value_or(0.0) << "\n";
+    std::cout << "refr w: " << acfg.refractWavelength << "\n";
 
     return 0;
 }