Squashed 'external/imgui/' content from commit 8326dabe5e7

git-subtree-dir: external/imgui
git-subtree-split: 8326dabe5e74a06cbd0adaf2b140c628bd5694c3

misc/cpp/imgui_stdlib.h

@@ -0,0 +1,21 @@
+// dear imgui: wrappers for C++ standard library (STL) types (std::string, etc.)
+// This is also an example of how you may wrap your own similar types.
+
+// Changelog:
+// - v0.10: Initial version. Added InputText() / InputTextMultiline() calls with std::string
+
+// See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+//   https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness
+
+#pragma once
+
+#include <string>
+
+namespace ImGui
+{
+    // ImGui::InputText() with std::string
+    // Because text input needs dynamic resizing, we need to setup a callback to grow the capacity
+    IMGUI_API bool  InputText(const char* label, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextMultiline(const char* label, std::string* str, const ImVec2& size = ImVec2(0, 0), ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextWithHint(const char* label, const char* hint, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+}