Use stricter C++ compiler flags

Enable more warnings, and treat all warnings as errors. This would have caught the incomplete switch fixed in f5f89be659.

cpp/src/api/api.cpp

@@ -43,8 +43,6 @@ LogLevel convert(uint8_t level) {
     return LogLevel::info;
   } else if (level == LIBLOOT_LOG_LEVEL_WARNING) {
     return LogLevel::warning;
-  } else if (level == LIBLOOT_LOG_LEVEL_ERROR) {
-    return LogLevel::error;
   } else {
     return LogLevel::error;
   }
@@ -67,10 +65,13 @@ loot::rust::LogLevel convert(LogLevel level) {
   }
 }
 
-void loggingCallback(uint8_t level, const char* message, void* context) {
-  auto& callback = *static_cast<Callback*>(context);
-
-  callback(convert(level), message);
+void loggingCallback(uint8_t level, const char* message, void* context) noexcept {
+  try {
+    auto& callback = *static_cast<Callback*>(context);
+    callback(convert(level), message);
+  } catch (...) {
+    // Can't do anything with the exception.
+  }
 }
 }
 

cpp/src/api/convert.cpp

@@ -31,6 +31,8 @@ std::optional<loot::EdgeType> convert(loot::rust::EdgeType edgeType) {
       return loot::EdgeType::tieBreak;
     case loot::rust::EdgeType::BlueprintMaster:
       return loot::EdgeType::blueprintMaster;
+    case loot::rust::EdgeType::None:
+      return std::nullopt;
     default:
       return std::nullopt;
   }

cpp/src/api/metadata/plugin_metadata.cpp

@@ -39,7 +39,7 @@ namespace {
 template<typename T>
 std::vector<T> mergeVectors(std::vector<T> first,
                             const std::vector<T>& second) {
-  const auto initialSizeOfFirst = first.size();
+  const auto initialSizeOfFirst = first.end() - first.begin();
   for (const auto& element : second) {
     const auto end = first.cbegin() + initialSizeOfFirst;