size_t Read(void *pBuf, size_t nCount);
// returns the number of bytes written
size_t Write(const void *pBuf, size_t nCount);
// returns true on success
size_t Read(void *pBuf, size_t nCount);
// returns the number of bytes written
size_t Write(const void *pBuf, size_t nCount);
// returns true on success