Add base::utf8() and utf8_const() wrappers

src/base/string.h

@@ -1,5 +1,5 @@
 // Aseprite Base Library
-// Copyright (c) 2001-2013, 2015 David Capello
+// Copyright (c) 2001-2016 David Capello
 //
 // This file is released under the terms of the MIT license.
 // Read LICENSE.txt for more information.
@@ -141,6 +141,30 @@ namespace base {
     }
   };
 
+  class utf8 {
+  public:
+    utf8(std::string& s) : m_begin(utf8_iterator(s.begin())),
+                           m_end(utf8_iterator(s.end())) {
+    }
+    const utf8_iterator& begin() const { return m_begin; }
+    const utf8_iterator& end() const { return m_end; }
+  private:
+    utf8_iterator m_begin;
+    utf8_iterator m_end;
+  };
+
+  class utf8_const {
+  public:
+    utf8_const(const std::string& s) : m_begin(utf8_const_iterator(s.begin())),
+                                       m_end(utf8_const_iterator(s.end())) {
+    }
+    const utf8_const_iterator& begin() const { return m_begin; }
+    const utf8_const_iterator& end() const { return m_end; }
+  private:
+    utf8_const_iterator m_begin;
+    utf8_const_iterator m_end;
+  };
+
 }
 
 #endif

src/base/string_tests.cpp

@@ -29,6 +29,29 @@ TEST(String, Utf8Conversion)
   ASSERT_EQ(a, c);
 }
 
+TEST(String, Utf8Wrapper)
+{
+  std::string a, b = "abc";
+  for (int ch : utf8(b))
+    a.push_back(ch);
+  EXPECT_EQ("abc", a);
+
+  std::string c;
+  for (int ch : utf8_const("def"))
+    c.push_back(ch);
+  EXPECT_EQ("def", c);
+
+  int i = 0;
+  for (int ch : utf8_const("\xE6\x97\xA5\xE6\x9C\xAC\xE8\xAA\x9E")) { // 日本語
+    switch (i++) {
+      case 0: EXPECT_EQ(ch, 0x65E5); break;
+      case 1: EXPECT_EQ(ch, 0x672C); break;
+      case 2: EXPECT_EQ(ch, 0x8A9E); break;
+      default: EXPECT_FALSE(true); break;
+    }
+  }
+}
+
 TEST(String, Utf8Iterator)
 {
   std::string a = "Hello";