========================================================================= */

Initialize state for writing a gzip file. Mark initialization by setting state->size to non-zero. Return -1 on a memory allocation failure, or 0

Open a gzip file either by name or file descriptor. */

Write len bytes from buf to file. Return the number of bytes written. If the returned value is less than len, then there was an error. */

Performs instance initialization including constructing a holder and registering the known instance. Should be called as soon as the `type` value_ptr

accessor overload required to override default assignment operator (templates are not allowed to replace default compiler-generated assignments).