message: TODO list update, comments
diff: // You may use this file to debug, understand or extend ImGui features but we don't provide any guarantee of forward compatibility!
  // Implement maths operators for ImVec2 (disabled by default to not collide with using IM_VEC2_CLASS_EXTRA along with your own math types+operators)
  // #define IMGUI_DEFINE_MATH_OPERATORS
  +// Define IM_PLACEMENT_NEW() macro helper.
  +// #define IMGUI_DEFINE_PLACEMENT_NEW
  #pragma once
  