source: vbox/trunk/src/libs/xpcom18a4/xpcom/string/public/nsTSubstringTuple.h@ 78394

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  /**
   * nsTSubstringTuple_CharT
   *
   * Represents a tuple of string fragments.  Built as a recursive binary tree.
   * It is used to implement the concatenation of two or more string objects.
   *
   * NOTE: This class is a private implementation detail and should never be 
   * referenced outside the string code.
   */
class nsTSubstringTuple_CharT
  {
    public:

      typedef CharT                      char_type;
      typedef nsCharTraits<char_type>    char_traits;

      typedef nsTSubstringTuple_CharT    self_type;
      typedef nsTSubstring_CharT         substring_type;
      typedef nsTString_CharT            string_type;
      typedef nsTAString_CharT           abstract_string_type;
      typedef nsTObsoleteAString_CharT   obsolete_string_type;

      typedef PRUint32                   size_type;

    public:

      nsTSubstringTuple_CharT(const abstract_string_type* a, const abstract_string_type* b)
        : mHead(nsnull)
        , mFragA(a)
        , mFragB(b) {}

      nsTSubstringTuple_CharT(const self_type& head, const abstract_string_type* b)
        : mHead(&head)
        , mFragA(nsnull) // this fragment is ignored when head != nsnull
        , mFragB(b) {}

        /**
         * computes the aggregate string length
         */
      NS_COM size_type Length() const;

        /**
         * writes the aggregate string to the given buffer.  bufLen is assumed
         * to be equal to or greater than the value returned by the Length()
         * method.  the string written to |buf| is not null-terminated.
         */
      NS_COM void WriteTo(char_type *buf, PRUint32 bufLen) const;

        /**
         * returns true if this tuple is dependent on (i.e., overlapping with)
         * the given char sequence.
         */
      NS_COM PRBool IsDependentOn(const char_type *start, const char_type *end) const;

    private:

      const self_type*            mHead;
      const abstract_string_type* mFragA;
      const abstract_string_type* mFragB;
  };

inline
const nsTSubstringTuple_CharT
operator+(const nsTAString_CharT& a, const nsTAString_CharT& b)
  {
    return nsTSubstringTuple_CharT(&a, &b);
  }

inline
const nsTSubstringTuple_CharT
operator+(const nsTSubstringTuple_CharT& head, const nsTAString_CharT& b)
  {
    return nsTSubstringTuple_CharT(head, &b);
  }