Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : /**
       8             :  * nsTLiteralString_CharT
       9             :  *
      10             :  * Stores a null-terminated, immutable sequence of characters.
      11             :  *
      12             :  * nsTString-lookalike that restricts its string value to a literal character
      13             :  * sequence. Can be implicitly cast to const nsTString& (the const is
      14             :  * essential, since this class's data are not writable). The data are assumed
      15             :  * to be static (permanent) and therefore, as an optimization, this class
      16             :  * does not have a destructor.
      17             :  */
      18             : class nsTLiteralString_CharT : public mozilla::detail::nsTStringRepr_CharT
      19             : {
      20             : public:
      21             : 
      22             :   typedef nsTLiteralString_CharT self_type;
      23             : 
      24             : public:
      25             : 
      26             :   /**
      27             :    * constructor
      28             :    */
      29             : 
      30             :   template<size_type N>
      31       30237 :   explicit nsTLiteralString_CharT(const char_type (&aStr)[N])
      32             :     : base_string_type(const_cast<char_type*>(aStr), N - 1,
      33       30237 :                        DataFlags::TERMINATED | DataFlags::LITERAL, ClassFlags(0))
      34             :   {
      35       30237 :   }
      36             : 
      37             :   /**
      38             :    * For compatibility with existing code that requires const ns[C]String*.
      39             :    * Use sparingly. If possible, rewrite code to use const ns[C]String&
      40             :    * and the implicit cast will just work.
      41             :    */
      42       22786 :   const nsTString_CharT& AsString() const
      43             :   {
      44       22786 :     return *reinterpret_cast<const nsTString_CharT*>(this);
      45             :   }
      46             : 
      47       22786 :   operator const nsTString_CharT&() const
      48             :   {
      49       22786 :     return AsString();
      50             :   }
      51             : 
      52             :   /**
      53             :    * Prohibit get() on temporaries as in nsLiteralCString("x").get().
      54             :    * These should be written as just "x", using a string literal directly.
      55             :    */
      56             : #if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
      57             :   char16ptr_t get() const && = delete;
      58             :   char16ptr_t get() const &
      59             : #else
      60             :   const char_type* get() const && = delete;
      61           0 :   const char_type* get() const &
      62             : #endif
      63             :   {
      64           0 :     return mData;
      65             :   }
      66             : 
      67             : private:
      68             : 
      69             :   // NOT TO BE IMPLEMENTED
      70             :   template<size_type N>
      71             :   nsTLiteralString_CharT(char_type (&aStr)[N]) = delete;
      72             : 
      73             :   self_type& operator=(const self_type&) = delete;
      74             : };
      75             : 
      76             : static_assert(sizeof(nsTLiteralString_CharT) == sizeof(nsTString_CharT),
      77             :               "nsTLiteralString_CharT can masquerade as nsTString_CharT, "
      78             :               "so they must have identical layout");