Revert 255397 "Fill out the rest of the StringPiece functions fo..."

trunk/src/base/strings/string_piece.h

Index: trunk/src/base/strings/string_piece.h
===================================================================
--- trunk/src/base/strings/string_piece.h	(revision 255491)
+++ trunk/src/base/strings/string_piece.h	(working copy)
@@ -39,124 +39,14 @@
 typedef BasicStringPiece<std::string> StringPiece;
 typedef BasicStringPiece<string16> StringPiece16;
 
-// internal --------------------------------------------------------------------
-
-// Many of the StringPiece functions use different implementations for the
-// 8-bit and 16-bit versions, and we don't want lots of template expansions in
-// this (very common) header that will slow down compilation.
-//
-// So here we define overloaded functions called by the StringPiece template.
-// For those that share an implementation, the two versions will expand to a
-// template internal to the .cc file.
 namespace internal {
 
-BASE_EXPORT void CopyToString(const StringPiece& self, std::string* target);
-BASE_EXPORT void CopyToString(const StringPiece16& self, string16* target);
-
-BASE_EXPORT void AppendToString(const StringPiece& self, std::string* target);
-BASE_EXPORT void AppendToString(const StringPiece16& self, string16* target);
-
-BASE_EXPORT size_t copy(const StringPiece& self,
-                        char* buf,
-                        size_t n,
-                        size_t pos);
-BASE_EXPORT size_t copy(const StringPiece16& self,
-                        char16* buf,
-                        size_t n,
-                        size_t pos);
-
-BASE_EXPORT size_t find(const StringPiece& self,
-                        const StringPiece& s,
-                        size_t pos);
-BASE_EXPORT size_t find(const StringPiece16& self,
-                        const StringPiece16& s,
-                        size_t pos);
-BASE_EXPORT size_t find(const StringPiece& self,
-                        char c,
-                        size_t pos);
-BASE_EXPORT size_t find(const StringPiece16& self,
-                        char16 c,
-                        size_t pos);
-
-BASE_EXPORT size_t rfind(const StringPiece& self,
-                         const StringPiece& s,
-                         size_t pos);
-BASE_EXPORT size_t rfind(const StringPiece16& self,
-                         const StringPiece16& s,
-                         size_t pos);
-BASE_EXPORT size_t rfind(const StringPiece& self,
-                         char c,
-                         size_t pos);
-BASE_EXPORT size_t rfind(const StringPiece16& self,
-                         char16 c,
-                         size_t pos);
-
-BASE_EXPORT size_t find_first_of(const StringPiece& self,
-                                 const StringPiece& s,
-                                 size_t pos);
-BASE_EXPORT size_t find_first_of(const StringPiece16& self,
-                                 const StringPiece16& s,
-                                 size_t pos);
-
-BASE_EXPORT size_t find_first_not_of(const StringPiece& self,
-                                     const StringPiece& s,
-                                     size_t pos);
-BASE_EXPORT size_t find_first_not_of(const StringPiece16& self,
-                                     const StringPiece16& s,
-                                     size_t pos);
-BASE_EXPORT size_t find_first_not_of(const StringPiece& self,
-                                     char c,
-                                     size_t pos);
-BASE_EXPORT size_t find_first_not_of(const StringPiece16& self,
-                                     char16 c,
-                                     size_t pos);
-
-BASE_EXPORT size_t find_last_of(const StringPiece& self,
-                                const StringPiece& s,
-                                size_t pos);
-BASE_EXPORT size_t find_last_of(const StringPiece16& self,
-                                const StringPiece16& s,
-                                size_t pos);
-BASE_EXPORT size_t find_last_of(const StringPiece& self,
-                                char c,
-                                size_t pos);
-BASE_EXPORT size_t find_last_of(const StringPiece16& self,
-                                char16 c,
-                                size_t pos);
-
-BASE_EXPORT size_t find_last_not_of(const StringPiece& self,
-                                    const StringPiece& s,
-                                    size_t pos);
-BASE_EXPORT size_t find_last_not_of(const StringPiece16& self,
-                                    const StringPiece16& s,
-                                    size_t pos);
-BASE_EXPORT size_t find_last_not_of(const StringPiece16& self,
-                                    char16 c,
-                                    size_t pos);
-BASE_EXPORT size_t find_last_not_of(const StringPiece& self,
-                                    char c,
-                                    size_t pos);
-
-BASE_EXPORT StringPiece substr(const StringPiece& self,
-                               size_t pos,
-                               size_t n);
-BASE_EXPORT StringPiece16 substr(const StringPiece16& self,
-                                 size_t pos,
-                                 size_t n);
-
-}  // namespace internal
-
-// BasicStringPiece ------------------------------------------------------------
-
 // Defines the types, methods, operators, and data members common to both
 // StringPiece and StringPiece16. Do not refer to this class directly, but
 // rather to BasicStringPiece, StringPiece, or StringPiece16.
-//
-// This is templatized by string class type rather than character type, so
-// BasicStringPiece<std::string> or BasicStringPiece<base::string16>.
-template <typename STRING_TYPE> class BasicStringPiece {
+template <typename STRING_TYPE> class StringPieceDetail {
  public:
-  // Standard STL container boilerplate.
+  // standard STL container boilerplate
   typedef size_t size_type;
   typedef typename STRING_TYPE::value_type value_type;
   typedef const value_type* pointer;
@@ -172,15 +62,15 @@
   // We provide non-explicit singleton constructors so users can pass
   // in a "const char*" or a "string" wherever a "StringPiece" is
   // expected (likewise for char16, string16, StringPiece16).
-  BasicStringPiece() : ptr_(NULL), length_(0) {}
-  BasicStringPiece(const value_type* str)
+  StringPieceDetail() : ptr_(NULL), length_(0) {}
+  StringPieceDetail(const value_type* str)
       : ptr_(str),
         length_((str == NULL) ? 0 : STRING_TYPE::traits_type::length(str)) {}
-  BasicStringPiece(const STRING_TYPE& str)
+  StringPieceDetail(const STRING_TYPE& str)
       : ptr_(str.data()), length_(str.size()) {}
-  BasicStringPiece(const value_type* offset, size_type len)
+  StringPieceDetail(const value_type* offset, size_type len)
       : ptr_(offset), length_(len) {}
-  BasicStringPiece(const typename STRING_TYPE::const_iterator& begin,
+  StringPieceDetail(const typename STRING_TYPE::const_iterator& begin,
                     const typename STRING_TYPE::const_iterator& end)
       : ptr_((end > begin) ? &(*begin) : NULL),
         length_((end > begin) ? (size_type)(end - begin) : 0) {}
@@ -251,113 +141,213 @@
     return STRING_TYPE::traits_type::compare(p, p2, N);
   }
 
-  // Sets the value of the given string target type to be the current string.
-  // This saves a temporary over doing |a = b.as_string()|
-  void CopyToString(STRING_TYPE* target) const {
+ protected:
+  const value_type* ptr_;
+  size_type     length_;
+};
+
+template <typename STRING_TYPE>
+const typename StringPieceDetail<STRING_TYPE>::size_type
+StringPieceDetail<STRING_TYPE>::npos =
+    typename StringPieceDetail<STRING_TYPE>::size_type(-1);
+
+// MSVC doesn't like complex extern templates and DLLs.
+#if !defined(COMPILER_MSVC)
+extern template class BASE_EXPORT StringPieceDetail<std::string>;
+extern template class BASE_EXPORT StringPieceDetail<string16>;
+#endif
+
+BASE_EXPORT void CopyToString(const StringPiece& self, std::string* target);
+BASE_EXPORT void AppendToString(const StringPiece& self, std::string* target);
+BASE_EXPORT StringPieceDetail<std::string>::size_type copy(
+    const StringPiece& self,
+    char* buf,
+    StringPieceDetail<std::string>::size_type n,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find(
+    const StringPiece& self,
+    char c,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type rfind(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type rfind(
+    const StringPiece& self,
+    char c,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_of(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_not_of(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_first_not_of(
+    const StringPiece& self,
+    char c,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_of(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_of(
+    const StringPiece& self,
+    char c,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_not_of(
+    const StringPiece& self,
+    const StringPiece& s,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPieceDetail<std::string>::size_type find_last_not_of(
+    const StringPiece& self,
+    char c,
+    StringPieceDetail<std::string>::size_type pos);
+BASE_EXPORT StringPiece substr(const StringPiece& self,
+                               StringPieceDetail<std::string>::size_type pos,
+                               StringPieceDetail<std::string>::size_type n);
+}  // namespace internal
+
+// Defines the template type that is instantiated as either StringPiece or
+// StringPiece16.
+template <typename STRING_TYPE> class BasicStringPiece :
+    public internal::StringPieceDetail<STRING_TYPE> {
+ public:
+  typedef typename internal::StringPieceDetail<STRING_TYPE>::value_type
+      value_type;
+  typedef typename internal::StringPieceDetail<STRING_TYPE>::size_type
+      size_type;
+
+  BasicStringPiece() {}
+  BasicStringPiece(const value_type*str)
+      : internal::StringPieceDetail<STRING_TYPE>(str) {}
+  BasicStringPiece(const STRING_TYPE& str)
+      : internal::StringPieceDetail<STRING_TYPE>(str) {}
+  BasicStringPiece(const value_type* offset, size_type len)
+      : internal::StringPieceDetail<STRING_TYPE>(offset, len) {}
+  BasicStringPiece(const typename STRING_TYPE::const_iterator& begin,
+                   const typename STRING_TYPE::const_iterator& end)
+      : internal::StringPieceDetail<STRING_TYPE>(begin, end) {}
+};
+
+// Specializes BasicStringPiece for std::string to add a few operations that
+// are not needed for string16.
+template <> class BasicStringPiece<std::string> :
+    public internal::StringPieceDetail<std::string> {
+ public:
+  BasicStringPiece() {}
+  BasicStringPiece(const char* str)
+      : internal::StringPieceDetail<std::string>(str) {}
+  BasicStringPiece(const std::string& str)
+      : internal::StringPieceDetail<std::string>(str) {}
+  BasicStringPiece(const char* offset, size_type len)
+      : internal::StringPieceDetail<std::string>(offset, len) {}
+  BasicStringPiece(const std::string::const_iterator& begin,
+                   const std::string::const_iterator& end)
+      : internal::StringPieceDetail<std::string>(begin, end) {}
+
+  // Prevent the following overload of set() from hiding the definitions in the
+  // base class.
+  using internal::StringPieceDetail<std::string>::set;
+
+  void set(const void* data, size_type len) {
+    ptr_ = reinterpret_cast<const value_type*>(data);
+    length_ = len;
+  }
+
+  void CopyToString(std::string* target) const {
     internal::CopyToString(*this, target);
   }
 
-  void AppendToString(STRING_TYPE* target) const {
+  void AppendToString(std::string* target) const {
     internal::AppendToString(*this, target);
   }
 
-  size_type copy(value_type* buf, size_type n, size_type pos = 0) const {
-    return internal::copy(*this, buf, n, pos);
-  }
-
   // Does "this" start with "x"
   bool starts_with(const BasicStringPiece& x) const {
-    return ((this->length_ >= x.length_) &&
-            (wordmemcmp(this->ptr_, x.ptr_, x.length_) == 0));
+    return ((length_ >= x.length_) &&
+            (wordmemcmp(ptr_, x.ptr_, x.length_) == 0));
   }
 
   // Does "this" end with "x"
   bool ends_with(const BasicStringPiece& x) const {
-    return ((this->length_ >= x.length_) &&
-            (wordmemcmp(this->ptr_ + (this->length_-x.length_),
-                        x.ptr_, x.length_) == 0));
+    return ((length_ >= x.length_) &&
+            (wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0));
   }
 
-  // find: Search for a character or substring at a given offset.
-  size_type find(const BasicStringPiece<STRING_TYPE>& s,
-                 size_type pos = 0) const {
+  size_type copy(char* buf, size_type n, size_type pos = 0) const {
+    return internal::copy(*this, buf, n, pos);
+  }
+
+  size_type find(const BasicStringPiece& s, size_type pos = 0) const {
     return internal::find(*this, s, pos);
   }
-  size_type find(value_type c, size_type pos = 0) const {
+
+  size_type find(char c, size_type pos = 0) const {
     return internal::find(*this, c, pos);
   }
 
-  // rfind: Reverse find.
-  size_type rfind(const BasicStringPiece& s,
-                  size_type pos = BasicStringPiece::npos) const {
+  size_type rfind(const BasicStringPiece& s, size_type pos = npos) const {
     return internal::rfind(*this, s, pos);
   }
-  size_type rfind(value_type c, size_type pos = BasicStringPiece::npos) const {
+
+  size_type rfind(char c, size_type pos = npos) const {
     return internal::rfind(*this, c, pos);
   }
 
-  // find_first_of: Find the first occurence of one of a set of characters.
-  size_type find_first_of(const BasicStringPiece& s,
-                          size_type pos = 0) const {
+  size_type find_first_of(const BasicStringPiece& s, size_type pos = 0) const {
     return internal::find_first_of(*this, s, pos);
   }
-  size_type find_first_of(value_type c, size_type pos = 0) const {
+
+  size_type find_first_of(char c, size_type pos = 0) const {
     return find(c, pos);
   }
 
-  // find_first_not_of: Find the first occurence not of a set of characters.
   size_type find_first_not_of(const BasicStringPiece& s,
                               size_type pos = 0) const {
     return internal::find_first_not_of(*this, s, pos);
   }
-  size_type find_first_not_of(value_type c, size_type pos = 0) const {
+
+  size_type find_first_not_of(char c, size_type pos = 0) const {
     return internal::find_first_not_of(*this, c, pos);
   }
 
-  // find_last_of: Find the last occurence of one of a set of characters.
   size_type find_last_of(const BasicStringPiece& s,
-                         size_type pos = BasicStringPiece::npos) const {
+                         size_type pos = npos) const {
     return internal::find_last_of(*this, s, pos);
   }
-  size_type find_last_of(value_type c,
-                         size_type pos = BasicStringPiece::npos) const {
+
+  size_type find_last_of(char c, size_type pos = npos) const {
     return rfind(c, pos);
   }
 
-  // find_last_not_of: Find the last occurence not of a set of characters.
   size_type find_last_not_of(const BasicStringPiece& s,
-                             size_type pos = BasicStringPiece::npos) const {
+                             size_type pos = npos) const {
     return internal::find_last_not_of(*this, s, pos);
   }
-  size_type find_last_not_of(value_type c,
-                             size_type pos = BasicStringPiece::npos) const {
+
+  size_type find_last_not_of(char c, size_type pos = npos) const {
     return internal::find_last_not_of(*this, c, pos);
   }
 
-  // substr.
-  BasicStringPiece substr(size_type pos,
-                          size_type n = BasicStringPiece::npos) const {
+  BasicStringPiece substr(size_type pos, size_type n = npos) const {
     return internal::substr(*this, pos, n);
   }
-
- 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);
-
 // MSVC doesn't like complex extern templates and DLLs.
 #if !defined(COMPILER_MSVC)
-extern template class BASE_EXPORT BasicStringPiece<std::string>;
+// We can't explicitly declare the std::string instantiation here because it was
+// already instantiated when specialized, above. Not only is it a no-op, but
+// currently it also crashes Clang (see http://crbug.com/107412).
 extern template class BASE_EXPORT BasicStringPiece<string16>;
 #endif
 
-// StingPiece operators --------------------------------------------------------
-
 BASE_EXPORT bool operator==(const StringPiece& x, const StringPiece& y);
 
 inline bool operator!=(const StringPiece& x, const StringPiece& y) {
@@ -382,8 +372,6 @@
   return !(x < y);
 }
 
-// StringPiece16 operators -----------------------------------------------------
-
 inline bool operator==(const StringPiece16& x, const StringPiece16& y) {
   if (x.size() != y.size())
     return false;
@@ -418,8 +406,6 @@
 
 }  // namespace base
 
-// Hashing ---------------------------------------------------------------------
-
 // We provide appropriate hash functions so StringPiece and StringPiece16 can
 // be used as keys in hash sets and maps.