Read datatype

[Quark-X10]

Description

HighFive provides the ability to commit datatypes to files with CompoundType::commit for example but does not provide the ability to open the previously commited datatypes.
This PR enhance the Node Traits to get the datatype stored in that node.

How to test this?

cmake ..
make -j8
make test

Test System
-OS: Ubuntu 22.04.2 LTS (WSL)
-Compiler: gcc 11.3.0
-Dependency versions: hdf5 1.10.7

[1uc]

Thank you, this looks interesting and I'll have a closer look later. In the meantime:

    template <typename Derivate>
    friend class NodeTraits;

is unfortunately a something that's a bit plagued by compiler errors, some compilers require this, while others insist that it's not present. Please see,
https://github.com/BlueBrain/HighFive/blob/master/include/highfive/H5Selection.hpp#L61-L64

for example. If CI complains, please adjust accordingly.

[Quark-X10]

Thank you for your quick reply.
I thought the protection was legacy since this type of declaration is unprotected elsewhere like here: https://github.com/BlueBrain/HighFive/blob/master/include/highfive/H5DataSet.hpp#L112-L113
CI does not seems to complain about that but i can correct if needed.
Moreover, I have some trouble to understand why the CI is complaining about a memory leak.

[alkino]

So the leak is not your responsibility (I think it was only not tested), and this is here: https://github.com/BlueBrain/HighFive/blob/master/include/highfive/H5DataType.hpp#L242
We have to free that.

[codecov]

Codecov Report

Merging #796 (e901735) into master (d2b1173) will increase coverage by 0.04%.
The diff coverage is 94.73%.

@@            Coverage Diff             @@
##           master     #796      +/-   ##
==========================================
+ Coverage   84.21%   84.25%   +0.04%     
==========================================
  Files          68       68              
  Lines        4776     4795      +19     
==========================================
+ Hits         4022     4040      +18     
- Misses        754      755       +1     

Impacted Files	Coverage Δ
include/highfive/H5DataType.hpp	89.88% <ø> (ø)
include/highfive/bits/H5Node_traits.hpp	100.00% <ø> (ø)
include/highfive/bits/H5Node_traits_misc.hpp	86.71% <80.00%> (-0.28%)	⬇️
tests/unit/tests_high_five_base.cpp	99.69% <100.00%> (+<0.01%)	⬆️

[1uc]

Nice work!