Documentation of GeometryInfo and ReferenceCell unclear

[nfehn]

The first paragraph in the documentation of GeometryInfo (https://www.dealii.org/developer/doxygen/deal.II/structGeometryInfo.html) says:

This class has been superseded by the ReferenceCell class – see there for more information.

Following the link "ReferenceCell", the first paragraph in the documentation of ReferenceCell (https://www.dealii.org/developer/doxygen/deal.II/classReferenceCell.html) says:

The purposes and intents of this class are described in the reference cell glossary entry.

Following the link "refence cell", the documentation in the glossary says:

The hypercube [0,1]dim, on which all parametric finite element shape functions are defined. Many properties of the reference cell are described by the GeometryInfo class.

again with a link to "GeometryInfo". A loop.

In particular, I hoped to find detailed information which parts of GeometryInfo can be used in the context of simplex. If GeometryInfo should not be used at all, this should be stated more clearly in the documentation of GeometryInfo in my opinion (the "superseded" comment is not explicit enough in my opinion), given that the above links redirected me to GeometryInfo in the end. I found neither the word "hypercube" nor "simplex" in GeometryInfo's documentation. Moreover, the glossary entry should probably be updated.

[bangerth]

Yes, we ought to fix this.

[nfehn]

Note that geometry info is also used in coding conventions, see https://www.dealii.org/developer/doxygen/deal.II/CodingConventions.html, which might be considered out-dated.