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