Backends: avoid missing -Wmissing-declaration warning. (#8087, #7997)

backends/imgui_impl_allegro5.cpp

@@ -311,6 +311,7 @@ static void ImGui_ImplAllegro5_SetClipboardText(ImGuiContext*, const char* text)
 #endif
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplAllegro5_KeyCodeToImGuiKey(int key_code);
 ImGuiKey ImGui_ImplAllegro5_KeyCodeToImGuiKey(int key_code)
 {
     switch (key_code)

backends/imgui_impl_glfw.cpp

@@ -187,6 +187,7 @@ static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData()
 // Functions
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int keycode, int scancode);
 ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int keycode, int scancode)
 {
     IM_UNUSED(scancode);

backends/imgui_impl_osx.mm

@@ -261,6 +261,7 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 // Functions
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplOSX_KeyCodeToImGuiKey(int key_code);
 ImGuiKey ImGui_ImplOSX_KeyCodeToImGuiKey(int key_code)
 {
     switch (key_code)

backends/imgui_impl_sdl2.cpp

@@ -182,6 +182,7 @@ static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport*, ImG
 }
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode);
 ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode)
 {
     IM_UNUSED(scancode);

backends/imgui_impl_sdl3.cpp

@@ -161,6 +161,7 @@ static void ImGui_ImplSDL3_PlatformSetImeData(ImGuiContext*, ImGuiViewport* view
 }
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplSDL3_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode);
 ImGuiKey ImGui_ImplSDL3_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode)
 {
     // Keypad doesn't have individual key values in SDL3

backends/imgui_impl_win32.cpp

@@ -421,6 +421,7 @@ void    ImGui_ImplWin32_NewFrame()
 
 // Map VK_xxx to ImGuiKey_xxx.
 // Not static to allow third-party code to use that if they want to (but undocumented)
+ImGuiKey ImGui_ImplWin32_KeyEventToImGuiKey(WPARAM wParam, LPARAM lParam);
 ImGuiKey ImGui_ImplWin32_KeyEventToImGuiKey(WPARAM wParam, LPARAM lParam)
 {
     // There is no distinct VK_xxx for keypad enter, instead it is VK_RETURN + KF_EXTENDED.