Work on wrapping types.

1 files changed, 57 insertions, 1 deletions

diff --git a/src/imgui_context.hpp b/src/imgui_context.hpp
index 94bac3d..435db9a 100644
--- a/src/imgui_context.hpp
+++ b/src/imgui_context.hpp
@@ -1,9 +1,10 @@
 #ifndef IMGUI_CONTEXT_HPP
 #define IMGUI_CONTEXT_HPP
 
+#include "gl_context.hpp"
 #include "sdl_context.hpp"
 #include "sdl_main_window.hpp"
-#include "gl_context.hpp"
+
 #include <imgui/imgui.h>
 
 namespace bookmouse {
@@ -24,6 +25,61 @@ class ImguiContext {
     SdlMainWindow& m_mainWindow;
 };
 
+template <typename Expr, typename Cleanup>
+class ConditionalRaii {
+  public:
+    template <typename... Args>
+    ConditionalRaii(Args&&... args) : m_expr{false}
+    {
+        Expr expr{};
+        m_expr = expr(std::forward<Args>(args)...);
+    }
+    ~ConditionalRaii()
+    {
+        Cleanup cleanup{};
+        if (m_expr) {
+            cleanup();
+        }
+    }
+    ConditionalRaii(const ConditionalRaii& rhs) = delete;
+    ConditionalRaii(ConditionalRaii&& rhs) = delete;
+    ConditionalRaii& operator=(const ConditionalRaii& rhs) = delete;
+    ConditionalRaii& operator=(ConditionalRaii&& rhs) = delete;
+    operator bool() const
+    {
+        return m_expr;
+    }
+
+  private:
+    bool m_expr;
+};
+
+#define STRUCT_FUNCTOR(FUNCTOR_NAME, FUNCTOR_FUNCTION)    \
+    struct FUNCTOR_NAME {                                 \
+        auto operator()() -> decltype(FUNCTOR_FUNCTION()) \
+        {                                                 \
+            return FUNCTOR_FUNCTION();                    \
+        }                                                 \
+    };
+
+#define STRUCT_FUNCTOR_ARGS(FUNCTOR_NAME, FUNCTOR_FUNCTION)         \
+    struct FUNCTOR_NAME {                                           \
+        template <typename... Args>                                 \
+        auto operator()(Args&&... args) -> /* FORCE BREAK */        \
+            decltype(FUNCTOR_FUNCTION(std::forward<Args>(args)...)) \
+        {                                                           \
+            return FUNCTOR_FUNCTION(std::forward<Args>(args)...);   \
+        }                                                           \
+    };
+
+STRUCT_FUNCTOR_ARGS(ImGuiBeginMenu, ImGui::BeginMenu)
+STRUCT_FUNCTOR(ImGuiEndMenu, ImGui::EndMenu)
+
+using ImguiMenu = ConditionalRaii<ImGuiBeginMenu, ImGuiEndMenu>;
+
+#undef STRUCT_FUNCTOR
+#undef STRUCT_FUNCTOR_ARGS
+
 } // namespace bookmouse
 
 #endif