v1 using observer pattern

.gitignore

@@ -0,0 +1,59 @@
+# CMake generated files
+CMakeCache.txt
+CMakeFiles/
+cmake_install.cmake
+Makefile
+*.cmake
+compile_commands.json
+
+# Build directories
+build/
+cmake-build-*/
+out/
+bin/
+lib/
+
+# C++ build artifacts
+*.o
+*.obj
+*.exe
+*.dll
+*.so
+*.dylib
+*.a
+*.lib
+
+# IDE and editor files
+.vscode/settings.json
+*.swp
+*.swo
+*~
+.idea/
+*.sublime-project
+*.sublime-workspace
+
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Temporary files
+*.tmp
+*.temp
+*.log
+
+# Package files
+*.deb
+*.rpm
+*.tar.gz
+*.zip
+
+# cache
+.cache
+
+# binary
+sub_notifs