4 files changed, 10 insertions, 10 deletions
diff --git a/include/cru/common/String.hpp b/include/cru/common/String.hpp
index 0a8d88a0..9996f617 100644
--- a/include/cru/common/String.hpp
+++ b/include/cru/common/String.hpp
@@ -273,6 +273,8 @@ class CRU_BASE_API StringView {
     return std::u16string_view(data(), size());
   }
 
+  std::string ToUtf8() const;
+
  private:
   const char16_t* ptr_;
   Index size_;
@@ -402,6 +404,9 @@ inline Index Utf16NextWord(StringView str, Index position,
                            bool* is_space = nullptr) {
   return Utf16NextWord(str.data(), str.size(), position, is_space);
 }
+
+String CRU_BASE_API ToLower(StringView s);
+String CRU_BASE_API ToUpper(StringView s);
 }  // namespace cru
 
 template <>
diff --git a/include/cru/common/StringUtil.hpp b/include/cru/common/StringUtil.hpp
index a24cf924..6c6b47b8 100644
--- a/include/cru/common/StringUtil.hpp
+++ b/include/cru/common/StringUtil.hpp
@@ -74,8 +74,7 @@ class CodePointIterator {
  public:
   bool operator==(const CodePointIterator& other) const {
     // You should compare iterator that iterate on the same string.
-    Expects(this->string_.data() == other.string_.data() &&
-            this->string_.size() == other.string_.size());
+    Expects(this->ptr_ == other.ptr_ && this->size_ == other.size_);
     return this->position_ == other.position_;
   }
   bool operator!=(const CodePointIterator& other) const {
@@ -222,6 +221,4 @@ Index CRU_BASE_API Utf16NextWord(const char16_t* ptr, Index size,
 
 char16_t CRU_BASE_API ToLower(char16_t c);
 char16_t CRU_BASE_API ToUpper(char16_t c);
-std::u16string CRU_BASE_API ToLower(std::u16string_view s);
-std::u16string CRU_BASE_API ToUpper(std::u16string_view s);
 }  // namespace cru
diff --git a/include/cru/ui/ThemeManager.hpp b/include/cru/ui/ThemeManager.hpp
index 1da29a0e..9908658c 100644
--- a/include/cru/ui/ThemeManager.hpp
+++ b/include/cru/ui/ThemeManager.hpp
@@ -35,7 +35,7 @@ class ThemeManager : public Object {
   }
 
   gsl::not_null<std::shared_ptr<platform::graphics::IBrush>> GetBrush(
-      std::u16string key);
+      StringView key);
 
  private:
   void Init();
@@ -43,8 +43,7 @@ class ThemeManager : public Object {
  private:
   Event<std::nullptr_t> theme_resource_change_event_;
   boost::property_tree::ptree theme_tree_;
-  std::unordered_map<std::u16string,
-                     std::shared_ptr<platform::graphics::IBrush>>
+  std::unordered_map<String, std::shared_ptr<platform::graphics::IBrush>>
       brushes_;
 };
 }  // namespace cru::ui
diff --git a/include/cru/ui/render/ScrollBar.hpp b/include/cru/ui/render/ScrollBar.hpp
index ce6f1b98..d6042719 100644
--- a/include/cru/ui/render/ScrollBar.hpp
+++ b/include/cru/ui/render/ScrollBar.hpp
@@ -13,7 +13,6 @@
 #include "cru/ui/controls/Control.hpp"
 #include "cru/ui/helper/ClickDetector.hpp"
 
-
 #include <gsl/pointers>
 #include <memory>
 #include <optional>
@@ -42,8 +41,8 @@ enum class ScrollBarAreaKind {
 enum class ScrollBarBrushUsageKind { Arrow, ArrowBackground, Slot, Thumb };
 enum class ScrollBarBrushStateKind { Normal, Hover, Press, Disable };
 
-std::u16string GenerateScrollBarThemeColorKey(ScrollBarBrushUsageKind usage,
-                                              ScrollBarBrushStateKind state);
+String GenerateScrollBarThemeColorKey(ScrollBarBrushUsageKind usage,
+                                      ScrollBarBrushStateKind state);
 
 class ScrollBar : public Object {
  public: