2 files changed, 35 insertions, 3 deletions
diff --git a/include/cru/common/Base.hpp b/include/cru/common/Base.hpp
index ff7ab31e..409c2b0e 100644
--- a/include/cru/common/Base.hpp
+++ b/include/cru/common/Base.hpp
@@ -44,4 +44,8 @@ struct Interface {
 }
 
 using Index = gsl::index;
+
+#define CRU_DEFINE_CLASS_LOG_TAG(tag) \
+ private:                             \
+  constexpr static std::string_view log_tag = tag;
 }  // namespace cru
diff --git a/include/cru/common/Logger.hpp b/include/cru/common/Logger.hpp
index bd16678b..f76e4626 100644
--- a/include/cru/common/Logger.hpp
+++ b/include/cru/common/Logger.hpp
@@ -15,7 +15,7 @@ enum class LogLevel { Debug, Info, Warn, Error };
 struct ILogSource : virtual Interface {
   // Write the string s. LogLevel is just a helper. It has no effect on the
   // content to write.
-  virtual void Write(LogLevel level, const std::string_view& s) = 0;
+  virtual void Write(LogLevel level, std::string_view s) = 0;
 };
 
 class StdioLogSource : public virtual ILogSource {
@@ -27,7 +27,7 @@ class StdioLogSource : public virtual ILogSource {
 
   ~StdioLogSource() override = default;
 
-  void Write(LogLevel level, const std::string_view& s) override {
+  void Write(LogLevel level, std::string_view s) override {
     // TODO: Emmm... Since it is buggy to use narrow char in UTF-8 on Windows. I
     // think this implementation might be broken. (However, I didn't test it.)
     // Maybe, I should detect Windows and use wide char (And I didn't test this
@@ -58,7 +58,8 @@ class Logger : public Object {
   void RemoveSource(ILogSource* source);
 
  public:
-  void Log(LogLevel level, const std::string_view& s);
+  void Log(LogLevel level, std::string_view s);
+  void Log(LogLevel level, std::string_view tag, std::string_view s);
 
  public:
   std::list<std::unique_ptr<ILogSource>> sources_;
@@ -89,4 +90,31 @@ void Error(TArgs&&... args) {
   Logger::GetInstance()->Log(LogLevel::Error,
                              fmt::format(std::forward<TArgs>(args)...));
 }
+
+template <typename... TArgs>
+void TagDebug([[maybe_unused]] std::string_view tag,
+              [[maybe_unused]] TArgs&&... args) {
+#ifdef CRU_DEBUG
+  Logger::GetInstance()->Log(LogLevel::Debug, tag,
+                             fmt::format(std::forward<TArgs>(args)...));
+#endif
+}
+
+template <typename... TArgs>
+void TagInfo(std::string_view tag, TArgs&&... args) {
+  Logger::GetInstance()->Log(LogLevel::Info, tag,
+                             fmt::format(std::forward<TArgs>(args)...));
+}
+
+template <typename... TArgs>
+void TagWarn(std::string_view tag, TArgs&&... args) {
+  Logger::GetInstance()->Log(LogLevel::Warn, tag,
+                             fmt::format(std::forward<TArgs>(args)...));
+}
+
+template <typename... TArgs>
+void TagError(std::string_view tag, TArgs&&... args) {
+  Logger::GetInstance()->Log(LogLevel::Error, tag,
+                             fmt::format(std::forward<TArgs>(args)...));
+}
 }  // namespace cru::log