BeginChild() return a bool analoguous to Begin(). if true you can skip submitting content.

imgui.cpp

@@ -2494,7 +2494,7 @@ void ImGui::EndTooltip()
     ImGui::End();
 }
 
-void ImGui::BeginChild(const char* str_id, ImVec2 size, bool border, ImGuiWindowFlags extra_flags)
+bool ImGui::BeginChild(const char* str_id, ImVec2 size, bool border, ImGuiWindowFlags extra_flags)
 {
     ImGuiState& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
@@ -2523,17 +2523,20 @@ void ImGui::BeginChild(const char* str_id, ImVec2 size, bool border, ImGuiWindow
     ImFormatString(title, IM_ARRAYSIZE(title), "%s.%s", window->Name, str_id);
 
     const float alpha = 1.0f;
-    ImGui::Begin(title, NULL, size, alpha, flags);
+    bool ret = ImGui::Begin(title, NULL, size, alpha, flags);
 
     if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
         g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
+
+    return ret;
 }
 
-void ImGui::BeginChild(ImGuiID id, ImVec2 size, bool border, ImGuiWindowFlags extra_flags)
+bool ImGui::BeginChild(ImGuiID id, ImVec2 size, bool border, ImGuiWindowFlags extra_flags)
 {
     char str_id[32];
     ImFormatString(str_id, IM_ARRAYSIZE(str_id), "child_%x", id);
-    ImGui::BeginChild(str_id, size, border, extra_flags);
+    bool ret = ImGui::BeginChild(str_id, size, border, extra_flags);
+    return ret;
 }
 
 void ImGui::EndChild()

imgui.h

@@ -159,8 +159,8 @@ namespace ImGui
     // Window
     IMGUI_API bool          Begin(const char* name = "Debug", bool* p_opened = NULL, ImVec2 size = ImVec2(0,0), float fill_alpha = -1.0f, ImGuiWindowFlags flags = 0);// return false when window is collapsed, so you can early out in your code. passing 'bool* p_opened' displays a Close button on the upper-right corner of the window, the pointed value will be set to false when the button is pressed.
     IMGUI_API void          End();
-    IMGUI_API void          BeginChild(const char* str_id, ImVec2 size = ImVec2(0,0), bool border = false, ImGuiWindowFlags extra_flags = 0);                         // size==0.0f: use remaining window size, size<0.0f: use remaining window size minus abs(size). on each axis.
-    IMGUI_API void          BeginChild(ImGuiID id, ImVec2 size = ImVec2(0,0), bool border = false, ImGuiWindowFlags extra_flags = 0);                                 // "
+    IMGUI_API bool          BeginChild(const char* str_id, ImVec2 size = ImVec2(0,0), bool border = false, ImGuiWindowFlags extra_flags = 0);                         // size==0.0f: use remaining window size, size<0.0f: use remaining window size minus abs(size). on each axis.
+    IMGUI_API bool          BeginChild(ImGuiID id, ImVec2 size = ImVec2(0,0), bool border = false, ImGuiWindowFlags extra_flags = 0);                                 // "
     IMGUI_API void          EndChild();
     IMGUI_API bool          GetWindowIsFocused();
     IMGUI_API ImVec2        GetContentRegionMax();                                              // window or current column boundaries, in windows coordinates