add operator==

otk/ustring.cc

@@ -229,6 +229,21 @@ ustring::value_type ustring::operator[](ustring::size_type i) const
   return utf8_get_char(utf8_offset_to_ptr(_string.data(), i));
 }
 
+bool ustring::operator==(const ustring &other) const
+{
+  return _string == other._string && _utf8 == other._utf8;
+}
+
+bool ustring::operator==(const std::string &other) const
+{
+  return _string == other;
+}
+
+bool ustring::operator==(const char *other) const
+{
+  return _string == other;
+}
+
 const char* ustring::data() const
 {
   return _string.data();

otk/ustring.hh

@@ -155,6 +155,12 @@ public:
   // No reference return; use replace() to write characters.
   value_type operator[](size_type i) const;
 
+  // compare strings
+
+  bool operator==(const ustring &other) const;
+  bool operator==(const std::string &other) const;
+  bool operator==(const char *other) const;
+
   // internal data
 
   const char* data()  const;