ImStrv: various tweaks and fixes. removed ImGuiTextRange from ImGuiTextFilter, fix test engine hooks, removed constructor only used twice.

imgui.cpp

@@ -2327,41 +2327,39 @@ bool ImGuiTextFilter::Draw(ImStrv label, float width)
     return value_changed;
 }
 
-void ImGuiTextFilter::ImGuiTextRange::split(char separator, ImVector<ImGuiTextRange>* out) const
+static void ImStrplit(ImStrv in, char separator, ImVector<ImStrv>* out)
 {
     out->resize(0);
-    const char* wb = b;
+    const char* wb = in.Begin;
     const char* we = wb;
-    while (we < e)
+    while (we < in.End)
     {
         if (*we == separator)
         {
-            out->push_back(ImGuiTextRange(wb, we));
+            out->push_back(ImStrv(wb, we));
             wb = we + 1;
         }
         we++;
     }
     if (wb != we)
-        out->push_back(ImGuiTextRange(wb, we));
+        out->push_back(ImStrv(wb, we));
 }
 
 void ImGuiTextFilter::Build()
 {
-    Filters.resize(0);
+    ImStrplit(ImStrv(InputBuf, InputBuf + strlen(InputBuf)), ',', &Filters);
-    ImGuiTextRange input_range(InputBuf, InputBuf + strlen(InputBuf));
-    input_range.split(',', &Filters);
 
     CountGrep = 0;
     for (int i = 0; i != Filters.Size; i++)
     {
-        ImGuiTextRange& f = Filters[i];
+        ImStrv& f = Filters[i];
-        while (f.b < f.e && ImCharIsBlankA(f.b[0]))
+        while (f.Begin < f.End && ImCharIsBlankA(f.Begin[0]))
-            f.b++;
+            f.Begin++;
-        while (f.e > f.b && ImCharIsBlankA(f.e[-1]))
+        while (f.End > f.Begin && ImCharIsBlankA(f.End[-1]))
-            f.e--;
+            f.End--;
         if (f.empty())
             continue;
-        if (Filters[i].b[0] != '-')
+        if (Filters[i].Begin[0] != '-')
             CountGrep += 1;
     }
 }
@@ -2372,23 +2370,23 @@ bool ImGuiTextFilter::PassFilter(ImStrv text) const
         return true;
 
     if (!text)
-        text.Begin = text.End = "";
+        text = "";
 
     for (int i = 0; i != Filters.Size; i++)
     {
-        const ImGuiTextRange& f = Filters[i];
+        const ImStrv& f = Filters[i];
         if (f.empty())
             continue;
-        if (f.b[0] == '-')
+        if (f.Begin[0] == '-')
         {
             // Subtract
-            if (ImStristr(text.Begin, text.End, f.b + 1, f.e) != NULL)
+            if (ImStristr(text.Begin, text.End, f.Begin + 1, f.End) != NULL)
                 return false;
         }
         else
         {
             // Grep
-            if (ImStristr(text.Begin, text.End, f.b, f.e) != NULL)
+            if (ImStristr(text.Begin, text.End, f.Begin, f.End) != NULL)
                 return true;
         }
     }
@@ -2419,6 +2417,8 @@ char ImGuiTextBuffer::EmptyString[1] = { 0 };
 void ImGuiTextBuffer::append(ImStrv str)
 {
     int len = (int)str.length();
+    if (len == 0)
+        return;
 
     // Add zero-terminator the first time
     const int write_off = (Buf.Size != 0) ? Buf.Size : 1;
@@ -2430,8 +2430,7 @@ void ImGuiTextBuffer::append(ImStrv str)
     }
 
     Buf.resize(needed_sz);
-    if (len > 0)
+    memcpy(&Buf[write_off - 1], str.Begin, (size_t)len);
-        memcpy(&Buf[write_off - 1], str.Begin, (size_t)len);
     Buf[write_off - 1 + len] = 0;
 }
 
@@ -3023,10 +3022,7 @@ const char* ImGui::GetStyleColorName(ImGuiCol idx)
 const char* ImGui::FindRenderedTextEnd(ImStrv text)
 {
     const char* text_display_end = text.Begin;
-    if (!text.End)
+    while (text_display_end < text.End && (text_display_end[0] != '#' || text_display_end[1] != '#'))
-        text.End = (const char*)-1;
-
-    while (text_display_end < text.End && *text_display_end != '\0' && (text_display_end[0] != '#' || text_display_end[1] != '#'))
         text_display_end++;
     return text_display_end;
 }
@@ -3039,17 +3035,14 @@ void ImGui::RenderText(ImVec2 pos, ImStrv text, bool hide_text_after_hash)
     ImGuiWindow* window = g.CurrentWindow;
 
     // Hide anything after a '##' string
-    const char* text_display_end;
     if (hide_text_after_hash)
-        text_display_end = FindRenderedTextEnd(text);
+        text.End = FindRenderedTextEnd(text);
-    else
-        text_display_end = text.End;
 
-    if (text.Begin != text_display_end)
+    if (text.Begin != text.End)
     {
-        window->DrawList->AddText(g.Font, g.FontSize, pos, GetColorU32(ImGuiCol_Text), ImStrv(text.Begin, text_display_end));
+        window->DrawList->AddText(g.Font, g.FontSize, pos, GetColorU32(ImGuiCol_Text), text);
         if (g.LogEnabled)
-            LogRenderedText(&pos, ImStrv(text.Begin, text_display_end));
+            LogRenderedText(&pos, text);
     }
 }
 
@@ -3099,16 +3092,16 @@ void ImGui::RenderTextClippedEx(ImDrawList* draw_list, const ImVec2& pos_min, co
 void ImGui::RenderTextClipped(const ImVec2& pos_min, const ImVec2& pos_max, ImStrv text, const ImVec2* text_size_if_known, const ImVec2& align, const ImRect* clip_rect)
 {
     // Hide anything after a '##' string
-    const char* text_display_end = FindRenderedTextEnd(text);
+    // FIXME-IMSTR: This is not new but should be moved out of there.
-    const int text_len = (int)(text_display_end - text.Begin);
+    text.End = FindRenderedTextEnd(text);
-    if (text_len == 0)
+    if (text.Begin == text.End)
         return;
 
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    RenderTextClippedEx(window->DrawList, pos_min, pos_max, ImStrv(text.Begin, text_display_end), text_size_if_known, align, clip_rect);
+    RenderTextClippedEx(window->DrawList, pos_min, pos_max, text, text_size_if_known, align, clip_rect);
     if (g.LogEnabled)
-        LogRenderedText(&pos_min, ImStrv(text.Begin, text_display_end));
+        LogRenderedText(&pos_min, text);
 }
 
 // Another overly complex function until we reorganize everything into a nice all-in-one helper.
@@ -3117,8 +3110,6 @@ void ImGui::RenderTextClipped(const ImVec2& pos_min, const ImVec2& pos_max, ImSt
 void ImGui::RenderTextEllipsis(ImDrawList* draw_list, const ImVec2& pos_min, const ImVec2& pos_max, float clip_max_x, float ellipsis_max_x, ImStrv text, const ImVec2* text_size_if_known)
 {
     ImGuiContext& g = *GImGui;
-    if (text.End == NULL)
-        text.End = FindRenderedTextEnd(text);
     const ImVec2 text_size = text_size_if_known ? *text_size_if_known : CalcTextSize(text, false, 0.0f);
 
     //draw_list->AddLine(ImVec2(pos_max.x, pos_min.y - 4), ImVec2(pos_max.x, pos_max.y + 4), IM_COL32(0, 0, 255, 255));
@@ -6039,7 +6030,7 @@ bool ImGui::Begin(ImStrv name, bool* p_open, ImGuiWindowFlags flags)
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    IM_ASSERT(name.Begin != NULL);                  // Window name required
+    IM_ASSERT(name.Begin != name.End);              // Window name required
     IM_ASSERT(g.WithinFrameScope);                  // Forgot to call ImGui::NewFrame()
     IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // Called ImGui::Render() or ImGui::EndFrame() and haven't called ImGui::NewFrame() again yet
 
@@ -11179,7 +11170,7 @@ bool ImGui::SetDragDropPayload(ImStrv type, const void* data, size_t data_size,
     if (cond == 0)
         cond = ImGuiCond_Always;
 
-    IM_ASSERT(type.Begin != NULL && "Payload type can not be empty");
+    IM_ASSERT(type.End - type.Begin > 0 && "Payload type can not be empty");
     IM_ASSERT(type.End - type.Begin < IM_ARRAYSIZE(payload.DataType) && "Payload type can be at most 32 characters long");
     IM_ASSERT((data != NULL && data_size > 0) || (data == NULL && data_size == 0));
     IM_ASSERT(cond == ImGuiCond_Always || cond == ImGuiCond_Once);
@@ -11704,12 +11695,12 @@ void ImGui::LoadIniSettingsFromDisk(ImStrv ini_filename)
     char* file_data = (char*)ImFileLoadToMemory(ini_filename, "rb", &file_data_size);
     if (!file_data)
         return;
-    LoadIniSettingsFromMemory(file_data, (size_t)file_data_size);
+    LoadIniSettingsFromMemory(ImStrv(file_data, file_data + file_data_size));
     IM_FREE(file_data);
 }
 
 // Zero-tolerance, no error reporting, cheap .ini parsing
-void ImGui::LoadIniSettingsFromMemory(ImStrv ini_data, size_t ini_size)
+void ImGui::LoadIniSettingsFromMemory(ImStrv ini_data)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);
@@ -11718,8 +11709,7 @@ void ImGui::LoadIniSettingsFromMemory(ImStrv ini_data, size_t ini_size)
 
     // For user convenience, we allow passing a non zero-terminated string (hence the ini_size parameter).
     // For our convenience and to make the code simpler, we'll also write zero-terminators within the buffer. So let's create a writable copy..
-    if (ini_size == 0)
+    const int ini_size = (int)ini_data.length();
-        ini_size = ini_data.length();
     g.SettingsIniData.Buf.resize((int)ini_size + 1);
     char* const buf = g.SettingsIniData.Buf.Data;
     char* const buf_end = buf + ini_size;

imgui.h

@@ -278,13 +278,14 @@ struct ImStrv
     ImStrv()                            { Begin = End = NULL; }
     ImStrv(const char* b)               { Begin = b; End = b ? b + strlen(b) : NULL; }
     ImStrv(const char* b, const char* e){ Begin = b; End = e ? e : b + strlen(b); }
-    ImStrv(const char* b, size_t size)  { Begin = b; End = b + size; }
     inline size_t length() const        { return (size_t)(End - Begin); }
     inline bool empty() const           { return Begin == End; }    // == "" or == NULL
     inline operator bool() const        { return Begin != NULL; }   // != NULL
 #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 string types and ImStrv.
 #endif
+    // private: bool operator==(ImStrv) { return false; } // [DEBUG] Uncomment to catch undesirable uses of operators
+    // private: bool operator!=(ImStrv) { return false; }
 };
 
 IM_MSVC_RUNTIME_CHECKS_RESTORE
@@ -939,7 +940,7 @@ namespace ImGui
     // - Set io.IniFilename to NULL to load/save manually. Read io.WantSaveIniSettings description about handling .ini saving manually.
     // - Important: default value "imgui.ini" is relative to current working dir! Most apps will want to lock this to an absolute path (e.g. same path as executables).
     IMGUI_API void          LoadIniSettingsFromDisk(ImStrv ini_filename);                       // call after CreateContext() and before the first call to NewFrame(). NewFrame() automatically calls LoadIniSettingsFromDisk(io.IniFilename).
-    IMGUI_API void          LoadIniSettingsFromMemory(ImStrv ini_data, size_t ini_size= 0);     // call after CreateContext() and before the first call to NewFrame() to provide .ini data from your own data source.
+    IMGUI_API void          LoadIniSettingsFromMemory(ImStrv ini_data);                         // call after CreateContext() and before the first call to NewFrame() to provide .ini data from your own data source.
     IMGUI_API void          SaveIniSettingsToDisk(ImStrv ini_filename);                         // this is automatically called (if io.IniFilename is not empty) a few seconds after any modification that should be reflected in the .ini file (and also by DestroyContext).
     IMGUI_API const char*   SaveIniSettingsToMemory(size_t* out_ini_size = NULL);               // return a zero-terminated string with the .ini data which you can save by your own mean. call when io.WantSaveIniSettings is set, then save data by your own mean and clear io.WantSaveIniSettings.
 
@@ -2103,7 +2104,7 @@ struct ImGuiInputTextCallbackData
     ImWchar             EventChar;      // Character input                      // Read-write   // [CharFilter] Replace character with another one, or set to zero to drop. return 1 is equivalent to setting EventChar=0;
     ImGuiKey            EventKey;       // Key pressed (Up/Down/TAB)            // Read-only    // [Completion,History]
     char*               Buf;            // Text buffer                          // Read-write   // [Resize] Can replace pointer / [Completion,History,Always] Only write to pointed data, don't replace the actual pointer!
-    int                 BufTextLen;     // Text length (in bytes)               // Read-write   // [Resize,Completion,History,Always] Exclude zero-terminator storage. In C land: == strlen(some_text), in C++ land: IM_IMSTR_LENGTH(string)
+    int                 BufTextLen;     // Text length (in bytes)               // Read-write   // [Resize,Completion,History,Always] Exclude zero-terminator storage. In C land: == strlen(some_text), in C++ land: string.length()
     int                 BufSize;        // Buffer size (in bytes) = capacity+1  // Read-only    // [Resize,Completion,History,Always] Include zero-terminator storage. In C land == ARRAYSIZE(my_char_array), in C++ land: string.capacity()+1
     bool                BufDirty;       // Set if you modify Buf/BufTextLen!    // Write        // [Completion,History,Always]
     int                 CursorPos;      //                                      // Read-write   // [Completion,History,Always]
@@ -2148,7 +2149,7 @@ struct ImGuiPayload
 
     ImGuiPayload()  { Clear(); }
     void Clear()    { SourceId = SourceParentId = 0; Data = NULL; DataSize = 0; memset(DataType, 0, sizeof(DataType)); DataFrameCount = -1; Preview = Delivery = false; }
-    bool IsDataType(ImStrv type) const      { return DataFrameCount != -1 && type == ImStrv(DataType); }
+    bool IsDataType(ImStrv type) const      { size_t len = type.length(); return DataFrameCount != -1 && memcmp(DataType, type.Begin, len) == 0 && DataType[len] == 0; }
     bool IsPreview() const                  { return Preview; }
     bool IsDelivery() const                 { return Delivery; }
 };
@@ -2209,20 +2210,9 @@ struct ImGuiTextFilter
     void                Clear()          { InputBuf[0] = 0; Build(); }
     bool                IsActive() const { return !Filters.empty(); }
 
-    // [Internal] FIXME-IMSTR: replace this with ImStrv, remove split as an internal function
+    char                InputBuf[256];
-    struct ImGuiTextRange
+    ImVector<ImStrv>    Filters;
-    {
+    int                 CountGrep;
-        const char*     b;
-        const char*     e;
-
-        ImGuiTextRange()                                { b = e = NULL; }
-        ImGuiTextRange(const char* _b, const char* _e)  { b = _b; e = _e; }
-        bool            empty() const                   { return b == e; }
-        IMGUI_API void  split(char separator, ImVector<ImGuiTextRange>* out) const;
-    };
-    char                    InputBuf[256];
-    ImVector<ImGuiTextRange>Filters;
-    int                     CountGrep;
 };
 
 // Helper: Growable text buffer for logging/accumulating text

imgui_demo.cpp

@@ -6768,7 +6768,7 @@ struct ExampleAppConsole
                     if (match_len > 0)
                     {
                         data->DeleteChars((int)(word_start - data->Buf), (int)(word_end - word_start));
-                        data->InsertChars(data->CursorPos, ImStrv(candidates[0], (size_t)match_len));
+                        data->InsertChars(data->CursorPos, ImStrv(candidates[0], candidates[0] + match_len));
                     }
 
                     // List matches

imgui_draw.cpp

@@ -1577,7 +1577,7 @@ void ImDrawList::AddText(const ImFont* font, float font_size, const ImVec2& pos,
 {
     if ((col & IM_COL32_A_MASK) == 0)
         return;
-    if (text.empty())
+    if (text.Begin == text.End)
         return;
 
     // Pull default font/size from the shared ImDrawListSharedData instance
@@ -3351,19 +3351,22 @@ const char* ImFont::CalcWordWrapPositionA(float scale, ImStrv text, float wrap_w
     float blank_width = 0.0f;
     wrap_width /= scale; // We work with unscaled widths to avoid scaling every characters
 
-    const char* word_end = text.Begin;
+    const char* text_begin = text.Begin;
+    const char* text_end = text.End;
+
+    const char* word_end = text_begin;
     const char* prev_word_end = NULL;
     bool inside_word = true;
 
-    const char* s = text.Begin;
+    const char* s = text_begin;
-    while (s < text.End)
+    while (s < text_end)
     {
         unsigned int c = (unsigned int)*s;
         const char* next_s;
         if (c < 0x80)
             next_s = s + 1;
         else
-            next_s = s + ImTextCharFromUtf8(&c, s, text.End);
+            next_s = s + ImTextCharFromUtf8(&c, s, text_end);
         if (c == 0)
             break;
 
@@ -3436,18 +3439,21 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, ImSt
     ImVec2 text_size = ImVec2(0, 0);
     float line_width = 0.0f;
 
+    const char* text_begin = text.Begin;
+    const char* text_end = text.End;
+
     const bool word_wrap_enabled = (wrap_width > 0.0f);
     const char* word_wrap_eol = NULL;
 
-    const char* s = text.Begin;
+    const char* s = text_begin;
-    while (s < text.End)
+    while (s < text_end)
     {
         if (word_wrap_enabled)
         {
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
             {
-                word_wrap_eol = CalcWordWrapPositionA(scale, ImStrv(s, text.End), wrap_width - line_width);
+                word_wrap_eol = CalcWordWrapPositionA(scale, ImStrv(s, text_end), wrap_width - line_width);
                 if (word_wrap_eol == s) // Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
                     word_wrap_eol++;    // +1 may not be a character start point in UTF-8 but it's ok because we use s >= word_wrap_eol below
             }
@@ -3461,7 +3467,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, ImSt
                 word_wrap_eol = NULL;
 
                 // Wrapping skips upcoming blanks
-                while (s < text.End)
+                while (s < text_end)
                 {
                     const char c = *s;
                     if (ImCharIsBlankA(c)) { s++; } else if (c == '\n') { s++; break; } else { break; }
@@ -3479,7 +3485,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, ImSt
         }
         else
         {
-            s += ImTextCharFromUtf8(&c, s, text.End);
+            s += ImTextCharFromUtf8(&c, s, text_end);
             if (c == 0) // Malformed UTF-8?
                 break;
         }
@@ -3552,34 +3558,35 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
 
     // Fast-forward to first visible line
     const char* s = text.Begin;
+    const char* text_end = text.End;
     if (y + line_height < clip_rect.y && !word_wrap_enabled)
-        while (y + line_height < clip_rect.y && s < text.End)
+        while (y + line_height < clip_rect.y && s < text_end)
         {
-            s = (const char*)memchr(s, '\n', text.End - s);
+            s = (const char*)memchr(s, '\n', text_end - s);
-            s = s ? s + 1 : text.End;
+            s = s ? s + 1 : text_end;
             y += line_height;
         }
 
     // For large text, scan for the last visible line in order to avoid over-reserving in the call to PrimReserve()
     // Note that very large horizontal line will still be affected by the issue (e.g. a one megabyte string buffer without a newline will likely crash atm)
-    if (text.End - s > 10000 && !word_wrap_enabled)
+    if (text_end - s > 10000 && !word_wrap_enabled)
     {
         const char* s_end = s;
         float y_end = y;
-        while (y_end < clip_rect.w && s_end < text.End)
+        while (y_end < clip_rect.w && s_end < text_end)
         {
-            s_end = (const char*)memchr(s_end, '\n', text.End - s_end);
+            s_end = (const char*)memchr(s_end, '\n', text_end - s_end);
-            s_end = s_end ? s_end + 1 : text.End;
+            s_end = s_end ? s_end + 1 : text_end;
             y_end += line_height;
         }
-        text.End = s_end;
+        text_end = s_end;
     }
-    if (s == text.End)
+    if (s == text_end)
         return;
 
     // Reserve vertices for remaining worse case (over-reserving is useful and easily amortized)
-    const int vtx_count_max = (int)(text.End - s) * 4;
+    const int vtx_count_max = (int)(text_end - s) * 4;
-    const int idx_count_max = (int)(text.End - s) * 6;
+    const int idx_count_max = (int)(text_end - s) * 6;
     const int idx_expected_size = draw_list->IdxBuffer.Size + idx_count_max;
     draw_list->PrimReserve(idx_count_max, vtx_count_max);
 
@@ -3596,7 +3603,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
             {
-                word_wrap_eol = CalcWordWrapPositionA(scale, ImStrv(s, text.End), wrap_width - (x - pos.x));
+                word_wrap_eol = CalcWordWrapPositionA(scale, ImStrv(s, text_end), wrap_width - (x - pos.x));
                 if (word_wrap_eol == s) // Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
                     word_wrap_eol++;    // +1 may not be a character start point in UTF-8 but it's ok because we use s >= word_wrap_eol below
             }
@@ -3608,7 +3615,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
                 word_wrap_eol = NULL;
 
                 // Wrapping skips upcoming blanks
-                while (s < text.End)
+                while (s < text_end)
                 {
                     const char c = *s;
                     if (ImCharIsBlankA(c)) { s++; } else if (c == '\n') { s++; break; } else { break; }
@@ -3625,7 +3632,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
         }
         else
         {
-            s += ImTextCharFromUtf8(&c, s, text.End);
+            s += ImTextCharFromUtf8(&c, s, text_end);
             if (c == 0) // Malformed UTF-8?
                 break;
         }

imgui_widgets.cpp

@@ -155,17 +155,20 @@ void ImGui::TextEx(ImStrv text, ImGuiTextFlags flags)
         return;
     ImGuiContext& g = *GImGui;
 
+    const char* text_begin = text.Begin;
+    const char* text_end = text.End;
+
     const ImVec2 text_pos(window->DC.CursorPos.x, window->DC.CursorPos.y + window->DC.CurrLineTextBaseOffset);
     const float wrap_pos_x = window->DC.TextWrapPos;
     const bool wrap_enabled = (wrap_pos_x >= 0.0f);
-    if (text.End - text.Begin > 2000 && !wrap_enabled)
+    if (text_end - text_begin > 2000 && !wrap_enabled)
     {
         // Long text!
         // Perform manual coarse clipping to optimize for long multi-line text
         // - From this point we will only compute the width of lines that are visible. Optimization only available when word-wrapping is disabled.
         // - We also don't vertically center the text within the line full height, which is unlikely to matter because we are likely the biggest and only item on the line.
         // - We use memchr(), pay attention that well optimized versions of those str/mem functions are much faster than a casually written loop.
-        const char* line = text.Begin;
+        const char* line = text_begin;
         const float line_height = GetTextLineHeight();
         ImVec2 text_size(0, 0);
 
@@ -177,11 +180,11 @@ void ImGui::TextEx(ImStrv text, ImGuiTextFlags flags)
             if (lines_skippable > 0)
             {
                 int lines_skipped = 0;
-                while (line < text.End && lines_skipped < lines_skippable)
+                while (line < text_end && lines_skipped < lines_skippable)
                 {
-                    const char* line_end = (const char*)memchr(line, '\n', text.End - line);
+                    const char* line_end = (const char*)memchr(line, '\n', text_end - line);
                     if (!line_end)
-                        line_end = text.End;
+                        line_end = text_end;
                     if ((flags & ImGuiTextFlags_NoWidthForLargeClippedText) == 0)
                         text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
                     line = line_end + 1;
@@ -192,17 +195,17 @@ void ImGui::TextEx(ImStrv text, ImGuiTextFlags flags)
         }
 
         // Lines to render
-        if (line < text.End)
+        if (line < text_end)
         {
             ImRect line_rect(pos, pos + ImVec2(FLT_MAX, line_height));
-            while (line < text.End)
+            while (line < text_end)
             {
                 if (IsClippedEx(line_rect, 0))
                     break;
 
-                const char* line_end = (const char*)memchr(line, '\n', text.End - line);
+                const char* line_end = (const char*)memchr(line, '\n', text_end - line);
                 if (!line_end)
-                    line_end = text.End;
+                    line_end = text_end;
                 text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
                 RenderText(pos, ImStrv(line, line_end), false);
                 line = line_end + 1;
@@ -213,11 +216,11 @@ void ImGui::TextEx(ImStrv text, ImGuiTextFlags flags)
 
             // Count remaining lines
             int lines_skipped = 0;
-            while (line < text.End)
+            while (line < text_end)
             {
-                const char* line_end = (const char*)memchr(line, '\n', text.End - line);
+                const char* line_end = (const char*)memchr(line, '\n', text_end - line);
                 if (!line_end)
-                    line_end = text.End;
+                    line_end = text_end;
                 if ((flags & ImGuiTextFlags_NoWidthForLargeClippedText) == 0)
                     text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
                 line = line_end + 1;
@@ -1618,7 +1621,7 @@ bool ImGui::BeginCombo(ImStrv label, ImStrv preview_value, ImGuiComboFlags flags
     if (flags & ImGuiComboFlags_CustomPreview)
     {
         g.ComboPreviewData.PreviewRect = ImRect(bb.Min.x, bb.Min.y, value_x2, bb.Max.y);
-        IM_ASSERT(!preview_value || preview_value[0] == 0);
+        IM_ASSERT(!preview_value);
         preview_value = NULL;
     }
 
@@ -2346,6 +2349,7 @@ bool ImGui::DragScalar(ImStrv label, ImGuiDataType data_type, void* p_data, floa
     if (!ItemAdd(total_bb, id, &frame_bb, temp_input_allowed ? ImGuiItemFlags_Inputable : 0))
         return false;
 
+    // FIXME-IMSTR
     char format_0[64];  // format may not end with \0
     const char* format = format_0;
     IM_ASSERT(format_p.End - format_p.Begin < IM_ARRAYSIZE(format_0));
@@ -2441,11 +2445,11 @@ bool ImGui::DragScalarN(ImStrv label, ImGuiDataType data_type, void* p_data, int
     }
     PopID();
 
-    const char* label_end = FindRenderedTextEnd(label);
+    label.End = FindRenderedTextEnd(label);
-    if (label.Begin != label_end)
+    if (label.Begin != label.End)
     {
         SameLine(0, g.Style.ItemInnerSpacing.x);
-        TextEx(ImStrv(label.Begin, label_end));
+        TextEx(label);
     }
 
     EndGroup();
@@ -2498,7 +2502,8 @@ bool ImGui::DragFloatRange2(ImStrv label, float* v_current_min, float* v_current
     PopItemWidth();
     SameLine(0, g.Style.ItemInnerSpacing.x);
 
-    TextEx(ImStrv(label.Begin, FindRenderedTextEnd(label)));
+    label.End = FindRenderedTextEnd(label);
+    TextEx(label);
     EndGroup();
     PopID();
 
@@ -2552,7 +2557,8 @@ bool ImGui::DragIntRange2(ImStrv label, int* v_current_min, int* v_current_max,
     PopItemWidth();
     SameLine(0, g.Style.ItemInnerSpacing.x);
 
-    TextEx(ImStrv(label.Begin, FindRenderedTextEnd(label)));
+    label.End = FindRenderedTextEnd(label);
+    TextEx(label);
     EndGroup();
     PopID();
 
@@ -2969,6 +2975,7 @@ bool ImGui::SliderScalar(ImStrv label, ImGuiDataType data_type, void* p_data, co
     if (!ItemAdd(total_bb, id, &frame_bb, temp_input_allowed ? ImGuiItemFlags_Inputable : 0))
         return false;
 
+    // FIXME-IMSTR
     char format_0[64];  // format may not end with \0
     const char* format = format_0;
     IM_ASSERT(format_p.End - format_p.Begin < IM_ARRAYSIZE(format_0));
@@ -3062,11 +3069,11 @@ bool ImGui::SliderScalarN(ImStrv label, ImGuiDataType data_type, void* v, int co
     }
     PopID();
 
-    const char* label_end = FindRenderedTextEnd(label);
+    label.End = FindRenderedTextEnd(label);
-    if (label.Begin != label_end)
+    if (label.Begin != label.End)
     {
         SameLine(0, g.Style.ItemInnerSpacing.x);
-        TextEx(ImStrv(label.Begin, label_end));
+        TextEx(label);
     }
 
     EndGroup();
@@ -3141,6 +3148,7 @@ bool ImGui::VSliderScalar(ImStrv label, const ImVec2& size, ImGuiDataType data_t
     if (!ItemAdd(frame_bb, id))
         return false;
 
+    // FIXME-IMSTR
     char format_0[64];  // format may not end with \0
     const char* format = format_0;
     IM_ASSERT(format_p.End - format_p.Begin < IM_ARRAYSIZE(format_0));
@@ -3391,6 +3399,7 @@ bool ImGui::InputScalar(ImStrv label, ImGuiDataType data_type, void* p_data, con
     ImGuiContext& g = *GImGui;
     ImGuiStyle& style = g.Style;
 
+    // FIXME-IMSTR
     char format_0[64];  // format may not end with \0
     const char* format = format_0;
     IM_ASSERT(format_p.End - format_p.Begin < IM_ARRAYSIZE(format_0));
@@ -3439,11 +3448,11 @@ bool ImGui::InputScalar(ImStrv label, ImGuiDataType data_type, void* p_data, con
         if (flags & ImGuiInputTextFlags_ReadOnly)
             EndDisabled();
 
-        const char* label_end = FindRenderedTextEnd(label);
+        label.End = FindRenderedTextEnd(label);
-        if (label.Begin != label_end)
+        if (label.Begin != label.End)
         {
             SameLine(0, style.ItemInnerSpacing.x);
-            TextEx(ImStrv(label.Begin, label_end));
+            TextEx(label);
         }
         style.FramePadding = backup_frame_padding;
 
@@ -3485,11 +3494,11 @@ bool ImGui::InputScalarN(ImStrv label, ImGuiDataType data_type, void* p_data, in
     }
     PopID();
 
-    const char* label_end = FindRenderedTextEnd(label);
+    label.End = FindRenderedTextEnd(label);
-    if (label.Begin != label_end)
+    if (label.Begin != label.End)
     {
         SameLine(0.0f, g.Style.ItemInnerSpacing.x);
-        TextEx(ImStrv(label.Begin, label_end));
+        TextEx(label);
     }
 
     EndGroup();
@@ -4857,11 +4866,11 @@ bool ImGui::ColorEdit4(ImStrv label, float col[4], ImGuiColorEditFlags flags)
     const float w_full = CalcItemWidth();
     const float w_button = (flags & ImGuiColorEditFlags_NoSmallPreview) ? 0.0f : (square_sz + style.ItemInnerSpacing.x);
     const float w_inputs = w_full - w_button;
-    const char* label_display_end = FindRenderedTextEnd(label);
     g.NextItemData.ClearFlags();
 
     BeginGroup();
     PushID(label);
+    label.End = FindRenderedTextEnd(label);
 
     // If we're not showing any slider there's no point in doing any HSV conversions
     const ImGuiColorEditFlags flags_untouched = flags;
@@ -5001,9 +5010,9 @@ bool ImGui::ColorEdit4(ImStrv label, float col[4], ImGuiColorEditFlags flags)
         if (BeginPopup("picker"))
         {
             picker_active_window = g.CurrentWindow;
-            if (label.Begin != label_display_end)
+            if (label.Begin != label.End)
             {
-                TextEx(ImStrv(label.Begin, label_display_end));
+                TextEx(label);
                 Spacing();
             }
             ImGuiColorEditFlags picker_flags_to_forward = ImGuiColorEditFlags_DataTypeMask_ | ImGuiColorEditFlags_PickerMask_ | ImGuiColorEditFlags_InputMask_ | ImGuiColorEditFlags_HDR | ImGuiColorEditFlags_NoAlpha | ImGuiColorEditFlags_AlphaBar;
@@ -5014,10 +5023,10 @@ bool ImGui::ColorEdit4(ImStrv label, float col[4], ImGuiColorEditFlags flags)
         }
     }
 
-    if (label.Begin != label_display_end && !(flags & ImGuiColorEditFlags_NoLabel))
+    if (label.Begin != label.End && !(flags & ImGuiColorEditFlags_NoLabel))
     {
         SameLine(0.0f, style.ItemInnerSpacing.x);
-        TextEx(ImStrv(label.Begin, label_display_end));
+        TextEx(label);
     }
 
     // Convert back
@@ -5580,10 +5589,10 @@ void ImGui::ColorTooltip(ImStrv text, const float* col, ImGuiColorEditFlags flag
     ImGuiContext& g = *GImGui;
 
     BeginTooltipEx(ImGuiTooltipFlags_OverridePreviousTooltip, ImGuiWindowFlags_None);
-    const char* text_end = text ? FindRenderedTextEnd(text) : text.Begin;
+    text.End = FindRenderedTextEnd(text);
-    if (text_end > text.Begin)
+    if (text.Begin != text.End)
     {
-        TextEx(ImStrv(text.Begin, text_end));
+        TextEx(text);
         Separator();
     }
 
@@ -5854,9 +5863,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, ImStrv label)
     const ImGuiStyle& style = g.Style;
     const bool display_frame = (flags & ImGuiTreeNodeFlags_Framed) != 0;
     const ImVec2 padding = (display_frame || (flags & ImGuiTreeNodeFlags_FramePadding)) ? style.FramePadding : ImVec2(style.FramePadding.x, ImMin(window->DC.CurrLineTextBaseOffset, style.FramePadding.y));
-
+    label.End = FindRenderedTextEnd(label);
-    if (!label.End)
-        label.End = FindRenderedTextEnd(label);
     const ImVec2 label_size = CalcTextSize(label, false);
 
     // We vertically grow up to current line height up the typical widget height.
@@ -6929,7 +6936,7 @@ bool ImGui::BeginMenuEx(ImStrv label, ImStrv icon, bool enabled)
         // (In a typical menu window where all items are BeginMenu() or MenuItem() calls, extra_w will always be 0.0f.
         //  Only when they are other items sticking out we're going to add spacing, yet only register minimum width into the layout system.
         popup_pos = ImVec2(pos.x, pos.y - style.WindowPadding.y);
-        float icon_w = (icon && icon[0]) ? CalcTextSize(icon, NULL).x : 0.0f;
+        float icon_w = icon ? CalcTextSize(icon, NULL).x : 0.0f;
         float checkmark_w = IM_FLOOR(g.FontSize * 1.20f);
         float min_w = window->DC.MenuColumns.DeclColumns(icon_w, label_size.x, 0.0f, checkmark_w); // Feedback to next frame
         float extra_w = ImMax(0.0f, GetContentRegionAvail().x - min_w);
@@ -7101,8 +7108,8 @@ bool ImGui::MenuItemEx(ImStrv label, ImStrv icon, ImStrv shortcut, bool selected
         // Menu item inside a vertical menu
         // (In a typical menu window where all items are BeginMenu() or MenuItem() calls, extra_w will always be 0.0f.
         //  Only when they are other items sticking out we're going to add spacing, yet only register minimum width into the layout system.
-        float icon_w = (icon && icon[0]) ? CalcTextSize(icon).x : 0.0f;
+        float icon_w = icon ? CalcTextSize(icon).x : 0.0f;
-        float shortcut_w = (shortcut && shortcut[0]) ? CalcTextSize(shortcut).x : 0.0f;
+        float shortcut_w = shortcut ? CalcTextSize(shortcut).x : 0.0f;
         float checkmark_w = IM_FLOOR(g.FontSize * 1.20f);
         float min_w = window->DC.MenuColumns.DeclColumns(icon_w, label_size.x, shortcut_w, checkmark_w); // Feedback for next frame
         float stretch_w = ImMax(0.0f, GetContentRegionAvail().x - min_w);
@@ -7954,6 +7961,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, ImStrv label, bool* p_open, ImGui
         flags |= ImGuiTabItemFlags_NoCloseButton;
 
     // Calculate tab contents size
+    label.End = FindRenderedTextEnd(label);
     ImVec2 size = TabItemCalcSize(label, p_open != NULL);
 
     // Acquire tab data
@@ -7982,7 +7990,8 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, ImStrv label, bool* p_open, ImGui
     // Append name with zero-terminator
     tab->NameOffset = (ImS32)tab_bar->TabsNames.size();
     tab_bar->TabsNames.append(label);
-    tab_bar->TabsNames.append(ImStrv("\0", 1));
+    char zero_c = 0;
+    tab_bar->TabsNames.append(ImStrv(&zero_c, &zero_c + 1));
 
     // Update selected tab
     if (tab_appearing && (tab_bar->Flags & ImGuiTabBarFlags_AutoSelectNewTabs) && tab_bar->NextSelectedTabId == 0)
@@ -8191,7 +8200,7 @@ void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabI
 void ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, ImStrv label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible, bool* out_just_closed, bool* out_text_clipped)
 {
     ImGuiContext& g = *GImGui;
-    ImVec2 label_size = CalcTextSize(label, true);
+    ImVec2 label_size = CalcTextSize(label);
 
     if (out_just_closed)
         *out_just_closed = false;