message: Make CoreDriver::write_tracking a simple scalar
diff: @@ -103,7 +103,7 @@ pub struct CoreDriver {
  pub increment: usize,
  pub filebacked: bool,
  #[cfg(hdf5_1_8_13)]
  - pub write_tracking: Option<usize>,
  + pub write_tracking: usize,
  }
  impl Default for CoreDriver {
  @@ -112,7 +112,7 @@ impl Default for CoreDriver {
  increment: 1024 * 1024,
  filebacked: false,
  #[cfg(hdf5_1_8_13)]
  - write_tracking: None,
  + write_tracking: 0,
  }
  }
  }
  @@ -439,8 +439,8 @@ impl FileAccessBuilder {
  }
  #[cfg(hdf5_1_8_13)]
  - pub fn write_tracking(&mut self, page_size: Option<usize>) -> &mut Self {
  - self.write_tracking = page_size;
  + pub fn write_tracking(&mut self, page_size: usize) -> &mut Self {
  + self.write_tracking = Some(page_size);
  self
  }
  @@ -495,9 +495,7 @@ impl FileAccessBuilder {
  #[cfg(hdf5_1_8_13)]
  {
  if let Some(page_size) = self.write_tracking {
  - h5try!(H5Pset_core_write_tracking(id, 1, page_size.max(1) as _));
  - } else {
  - h5try!(H5Pset_core_write_tracking(id, 0, 1));
  + h5try!(H5Pset_core_write_tracking(id, (page_size > 0) as _, page_size.max(1) as _));
  }
  }
  Ok(())
  @@ -643,9 +641,9 @@ impl FileAccess {
  &mut page_size as *mut _,
  ));
  if is_enabled > 0 {
  - drv.write_tracking = Some(page_size as _);
  + drv.write_tracking = page_size;
  } else {
  - drv.write_tracking = None;
  + drv.write_tracking = 0;
  }
  }
  Ok(drv)
  