Adapters and the return value problem¶
The return value problem¶
A group in HDF5 can be considered as a container for other groups and
datasets. This raises a simple question: what to return from a method of
group_t which provides access to the children of the group?
h5::group_t group = ....;
???? child = group["sensors"];
The return value could be either a dataset or a group. However, as the true nature of a child can only be determined at runtime it is virtually impossible to pin down the required data type at compile time.
We can, however, pin down some general statements about the returned object
it is either a group or a dataset, it cannot be both
There are several options how to deal with this issue which shall be discussed in this chapter.