string_util support for joining strings using strings not just chars.

base/string_util.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file defines utility functions for working with strings.
 
 #ifndef BASE_STRING_UTIL_H_
 #define BASE_STRING_UTIL_H_
 
 #include <ctype.h>
@@ skipping 490 matching lines @@
                             std::vector<std::string>* tokens);
 BASE_EXPORT size_t Tokenize(const base::StringPiece& str,
                             const base::StringPiece& delimiters,
                             std::vector<base::StringPiece>* tokens);
 
 // Does the opposite of SplitString().
 BASE_EXPORT string16 JoinString(const std::vector<string16>& parts, char16 s);
 BASE_EXPORT std::string JoinString(
     const std::vector<std::string>& parts, char s);
 
+// Join |parts| using |separator|.
+BASE_EXPORT std::string JoinString(
+    const std::vector<std::string>& parts,
+    const std::string& separator);
+BASE_EXPORT string16 JoinString(
+    const std::vector<string16>& parts,
+    const string16& separator);
+
 // Replace $1-$2-$3..$9 in the format string with |a|-|b|-|c|..|i| respectively.
 // Additionally, any number of consecutive '$' characters is replaced by that
 // number less one. Eg $$->$, $$$->$$, etc. The offsets parameter here can be
 // NULL. This only allows you to use up to nine replacements.
 BASE_EXPORT string16 ReplaceStringPlaceholders(
     const string16& format_string,
     const std::vector<string16>& subst,
     std::vector<size_t>* offsets);
 
 BASE_EXPORT std::string ReplaceStringPlaceholders(
@@ skipping 38 matching lines @@
 #elif defined(WCHAR_T_IS_UTF32)
   typedef uint32 Unsigned;
 #endif
 };
 template<>
 struct ToUnsigned<short> {
   typedef unsigned short Unsigned;
 };
 
 #endif  // BASE_STRING_UTIL_H_