ImStr: rework toward ensuring End is always set to constant can be compile time calculated

Author: ocornut

imgui.cpp

@@ -1362,7 +1362,6 @@ const char* ImStristr(const char* haystack, const char* haystack_end, const char
 
 const char* ImStrstr(ImStr haystack, ImStr needle)
 {
-    IM_IMSTR_ENSURE_HAS_END(needle);
     const char un0 = (char)*needle.Begin;
     while ((!haystack.End && *haystack.Begin) || (haystack.End && haystack.Begin < haystack.End))
     {
@@ -2085,8 +2084,7 @@ bool ImGuiTextFilter::PassFilter(ImStr text) const
     if (Filters.empty())
         return true;
 
-    IM_IMSTR_ENSURE_HAS_END(text);
-    if (text.Empty())
+    if (text.Empty()) // FIXME-IMSTR
         text.Begin = text.End = "";
 
     for (int i = 0; i != Filters.Size; i++)
@@ -2661,14 +2659,9 @@ void ImGui::RenderText(ImVec2 pos, ImStr text, bool hide_text_after_hash)
     // Hide anything after a '##' string
     const char* text_display_end;
     if (hide_text_after_hash)
-    {
         text_display_end = FindRenderedTextEnd(text);
-    }
     else
-    {
-        IM_IMSTR_ENSURE_HAS_END(text);
         text_display_end = text.End;
-    }
 
     if (text.Begin != text_display_end)
     {
@@ -2682,7 +2675,6 @@ void ImGui::RenderTextWrapped(ImVec2 pos, ImStr text, float wrap_width)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    IM_IMSTR_ENSURE_HAS_END(text);
 
     if (text.Begin != text.End)
     {
@@ -2918,7 +2910,6 @@ ImGuiID ImGuiWindow::GetID(ImStr str)
     ImGui::KeepAliveID(id);
 #ifdef IMGUI_ENABLE_TEST_ENGINE
     ImGuiContext& g = *GImGui;
-    IM_IMSTR_ENSURE_HAS_END(str);
     IMGUI_TEST_ENGINE_ID_INFO2(id, ImGuiDataType_String, str.Begin, str.End);
 #endif
     return id;
@@ -2954,7 +2945,6 @@ ImGuiID ImGuiWindow::GetIDNoKeepAlive(ImStr str)
     ImGuiID id = ImHashStr(str, seed);
 #ifdef IMGUI_ENABLE_TEST_ENGINE
     ImGuiContext& g = *GImGui;
-    IM_IMSTR_ENSURE_HAS_END(str);
     IMGUI_TEST_ENGINE_ID_INFO2(id, ImGuiDataType_String, str.Begin, str.End);
 #endif
     return id;
@@ -4414,7 +4404,6 @@ ImVec2 ImGui::CalcTextSize(ImStr text, bool hide_text_after_double_hash, float w
 {
     ImGuiContext& g = *GImGui;
 
-    IM_IMSTR_ENSURE_HAS_END(text);
     if (hide_text_after_double_hash)
         text.End = FindRenderedTextEnd(text);      // Hide anything after a '##' string
 

imgui.h

@@ -243,20 +243,19 @@ struct ImVec4
 #endif
 };
 
-#define IM_IMSTR_LENGTH(s)          (s.Begin ? (s.End ? (size_t)(s.End - s.Begin) : strlen(s.Begin)) : 0)
-#define IM_IMSTR_ENSURE_HAS_END(s)  if (s.End == NULL) s.End = s.Begin + strlen(s.Begin)
+#define IM_IMSTR_LENGTH(s)          (size_t)(s.End - s.Begin)
 
 // String view class.
 #define IMGUI_HAS_IMSTR 1
 struct ImStr
 {
     const char* Begin;
     const char* End;
-    ImStr() { Begin = End = NULL; }
-    ImStr(const char* b) { Begin = b; End = NULL; }
-    ImStr(const char* b, const char* e) { Begin = b; End = e; }
-    ImStr(const char* b, size_t size) { Begin = b; End = b + size; }
-    bool Empty() const { return Begin == NULL || Begin == End || Begin[0] == 0; }
+    ImStr()                             { Begin = End = NULL; }
+    ImStr(const char* b)                { Begin = b; End = b ? b + strlen(b) : NULL; }
+    ImStr(const char* b, const char* e) { Begin = b; End = e ? e : b + strlen(b); }
+    ImStr(const char* b, size_t size)   { Begin = b; End = b + size; }
+    bool Empty() const                  { return Begin == End || Begin[0] == 0; } // FIXME: Ambiguous
     // void EnsureHasEnd() { if (End == NULL) End = Begin + Length(); }
     // size_t Length() const
     // {
@@ -275,10 +274,10 @@ struct ImStr
             return memcmp(Begin, other.Begin, len) == 0;
         return false;
     }
-    operator bool() const { return Begin != NULL; }
-    char operator[](int index) const { return Begin[index]; }
+    inline operator bool() const { return Begin != NULL; }
+    inline char operator[](int index) const { return Begin[index]; }
 #ifdef IM_IMSTR_CLASS_EXTRA
-    IM_IMSTR_CLASS_EXTRA     // Define additional constructors and implicit cast operators in imconfig.h to convert back and forth between your math types and ImStr.
+    IM_IMSTR_CLASS_EXTRA     // Define additional constructors and implicit cast operators in imconfig.h to convert back and forth between your string types and ImStr.
 #endif
 };
 

imgui_draw.cpp

@@ -1326,7 +1326,6 @@ void ImDrawList::AddText(const ImFont* font, float font_size, const ImVec2& pos,
     if ((col & IM_COL32_A_MASK) == 0)
         return;
 
-    IM_IMSTR_ENSURE_HAS_END(text);
     if (text.Empty())
         return;
 
@@ -3019,7 +3018,6 @@ const char* ImFont::CalcWordWrapPositionA(float scale, ImStr text, float wrap_wi
 
     // Cut words that cannot possibly fit within one line.
     // e.g.: "The tropical fish" with ~5 characters worth of width --> "The tr" "opical" "fish"
-    IM_IMSTR_ENSURE_HAS_END(text);
 
     float line_width = 0.0f;
     float word_width = 0.0f;
@@ -3105,8 +3103,6 @@ const char* ImFont::CalcWordWrapPositionA(float scale, ImStr text, float wrap_wi
 
 ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, ImStr text, const char** remaining) const
 {
-    IM_IMSTR_ENSURE_HAS_END(text);
-
     const float line_height = size;
     const float scale = size / FontSize;
 
@@ -3210,8 +3206,6 @@ void ImFont::RenderChar(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
 
 void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col, const ImVec4& clip_rect, ImStr text, float wrap_width, bool cpu_fine_clip) const
 {
-    IM_IMSTR_ENSURE_HAS_END(text); // ImGui:: functions generally already provides a valid text_end, so this is merely to handle direct calls.
-
     // Align to be pixel perfect
     pos.x = IM_FLOOR(pos.x);
     pos.y = IM_FLOOR(pos.y);

imgui_widgets.cpp

@@ -148,7 +148,6 @@ void ImGui::TextEx(ImStr text, ImGuiTextFlags flags)
         return;
 
     ImGuiContext& g = *GImGui;
-    IM_IMSTR_ENSURE_HAS_END(text);
 
     const ImVec2 text_pos(window->DC.CursorPos.x, window->DC.CursorPos.y + window->DC.CurrLineTextBaseOffset);
     const float wrap_pos_x = window->DC.TextWrapPos;
@@ -4182,7 +4181,6 @@ bool ImGui::InputTextEx(ImStr label, ImStr hint, char* buf, int buf_size, const
             if (ImStr clipboard = GetClipboardText())
             {
                 // Filter pasted buffer
-                IM_IMSTR_ENSURE_HAS_END(clipboard);
                 const int clipboard_len = (int)IM_IMSTR_LENGTH(clipboard);
                 ImWchar* clipboard_filtered = (ImWchar*)IM_ALLOC((clipboard_len + 1) * sizeof(ImWchar));
                 int clipboard_filtered_len = 0;
@@ -4392,7 +4390,6 @@ bool ImGui::InputTextEx(ImStr label, ImStr hint, char* buf, int buf_size, const
     const char* buf_display_end = NULL; // We have specialized paths below for setting the length
     if (is_displaying_hint)
     {
-        IM_IMSTR_ENSURE_HAS_END(hint);
         buf_display = hint.Begin;
         buf_display_end = hint.End;
     }