[wip] Add LiteralStringPiece which templatizes based on character length

base/strings/string_piece.h

 // Copyright (c) 2012 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.
 // Copied from strings/stringpiece.h with modifications
 //
 // A string-like object that points to a sized piece of memory.
 //
 // You can use StringPiece as a function or method parameter.  A StringPiece
 // parameter can receive a double-quoted string literal argument, a "const
 // char*" argument, a string argument, or a StringPiece argument with no data
@@ skipping 349 matching lines @@
  protected:
   const value_type* ptr_;
   size_type     length_;
 };
 
 template <typename STRING_TYPE>
 const typename BasicStringPiece<STRING_TYPE>::size_type
 BasicStringPiece<STRING_TYPE>::npos =
     typename BasicStringPiece<STRING_TYPE>::size_type(-1);
 
+template <size_t size>
+inline StringPiece LiteralStringPiece(const char (&array)[size]) {
+  return StringPiece(array, size - 1);
+}
+
 // MSVC doesn't like complex extern templates and DLLs.
 #if !defined(COMPILER_MSVC)
 extern template class BASE_EXPORT BasicStringPiece<std::string>;
 extern template class BASE_EXPORT BasicStringPiece<string16>;
 #endif
 
 // StingPiece operators --------------------------------------------------------
 
 BASE_EXPORT bool operator==(const StringPiece& x, const StringPiece& y);
 
@@ skipping 75 matching lines @@
 };
 struct StringPiece16Hash {
   std::size_t operator()(const StringPiece16& sp16) const {
     HASH_STRING_PIECE(StringPiece16, sp16);
   }
 };
 
 }  // namespace base
 
 #endif  // BASE_STRINGS_STRING_PIECE_H_