message: Add Datatype::{conv_to,conv_from,is}()
diff: @@ -148,6 +148,18 @@ impl Datatype {
  })
  }
  + pub fn conv_to<T: H5Type>(&self) -> Option<Conversion> {
  + Datatype::from_type::<T>().ok().and_then(|dtype| self.conv_path(dtype))
  + }
  +
  + pub fn conv_from<T: H5Type>(&self) -> Option<Conversion> {
  + Datatype::from_type::<T>().ok().and_then(|dtype| dtype.conv_path(self))
  + }
  +
  + pub fn is<T: H5Type>(&self) -> bool {
  + Datatype::from_type::<T>().ok().map(|dtype| &dtype == self).unwrap_or(false)
  + }
  +
  pub(crate) fn ensure_convertible(&self, dst: &Datatype, required: Conversion) -> Result<()> {
  // TODO: more detailed error messages after Debug/Display are implemented for Datatype
  if let Some(conv) = self.conv_path(dst) {
  