Function1/CSV/CSV.C: Need to move explicit template specializations to a separate file (ex: CSVTemplates.C)

Summary

The file src/OpenFOAM/primitives/functions/Function1/CSV/CSV.C contains 2 explicit template specializations for the member function ::readValue(). Those will be reported as multiply-defined by the linker when the corresponding file CSV.H gets included in the source code of a custom-build library depending on the core library libOpenFOAM.

Steps to reproduce

Simply add the statement "#include CSV.H" in the source code of any custom-made library depending on the libOpenFOAM library.

Since the file CSV.C is included at the bottom of the file CSV.H, the 2 explicit template specializations will be reported as multiply-defined by the linker.

Example case

This is a compilation issue.

What is the current bug behaviour?

The custom-build library fails to link. An error message is written at the console stating that 2 instances of the template specialized member function ::readValue() are multiply-defined, and are first defined at lines 72 and 82 of src/OpenFOAM/primitives/functions/Function1/CSV/CSV.C

What is the expected correct behaviour?

Proper linking of the custom-made library when using the class Foam::Function1Types::CSV.

Relevant logs and/or images

Environment information

• OpenFOAM version : probably all versions of OpenFOAM since the files CSV.[CH] were introduced.
• Operating system : Fedora 33
• Hardware info :
• Compiler : gcc 10.3.1

Possible fixes

Move the following 2 explicit template specializations to a separate file like src/OpenFOAM/primitives/functions/Function1/CSV/CSVTemplates.C

Add the file CSVTemplates.C to the file src/OpenFOAM/Make/files.

From src/OpenFOAM/primitives/functions/Function1/CSV/CSV.C

     65 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
     66 
     67 template<>
     68 Foam::label Foam::Function1Types::CSV<Foam::label>::readValue
     69 (
     70     const List<string>& strings
     71 ) const
     72 {
     73     return readLabel(strings[componentColumns_[0]]);
     74 }
     75 
     76 
     77 template<>
     78 Foam::scalar Foam::Function1Types::CSV<Foam::scalar>::readValue
     79 (
     80     const List<string>& strings
     81 ) const
     82 {
     83     return readScalar(strings[componentColumns_[0]]);
     84 }