std::basic_stringbuf::init_buf_ptrs(3)

NAME
std::basic_stringbuf::init_buf_ptrs - std::basic_stringbuf::init_buf_ptrs

Synopsis
   void init_buf_ptrs(); (exposition only*)
   Initializes the input and output sequences from buf according to mode. buf and mode
   are exposition-only data members of *this.
   Immediately after this function returns:
     * If std::ios_base::out is set in mode, pbase() points to buf.front() and epptr()
       >= pbase() + buf.size() is true;
          * in addition, if std::ios_base::ate is set in mode, pptr() == pbase() +
            buf.size() is true,
          * otherwise pptr() == pbase() is true.
     * If std::ios_base::in is set in mode, eback() points to buf.front(), and gptr()
       == eback() && egptr() == eback() + buf.size() is true.

Notes
   For efficiency reasons, stream buffer operations can violate invariants of buf while
   it is held encapsulated in the std::basic_stringbuf, e.g., by writing to characters
   in the range [buf.data() + buf.size(), buf.data() + buf.capacity()).
   All operations retrieving a std::basic_string from buf ensure that the
   std::basic_string invariants hold on the returned value.
   Defect reports
   The following behavior-changing defect reports were applied retroactively to
   previously published C++ standards.
      DR Applied to Behavior as published Correct behavior
                       calling init_buf_ptrs() made makes
   LWG 1448 C++98 pptr() == pbase() + buf.data() pptr() == pbase() +
                       for streams that are both input and output buf.size()
                       streams for append streams