Attempting to create Ifpack2 conditioner gets me errors about "incompatible cv-qualifiers"

[jjramsey]

I'm trying to initialize a preconditioner preCond with the following code:

Ifpack2::Factory precondFactory;
Teuchos::RCP<Ifpack2::Preconditioner<Sc_type, LO_type, GO_type> >
        precond = precondFactory.create(precondType, Kglobal);

where Kglobal is declared as follows:

Teuchos::RCP<TpMatrix> Kglobal(new TpMatrix(graph));

and TpMatrix is a typedef for Tpetra::FECrsMatrix<Sc_type, LO_type, GO_type>, with Sc_type being double, LO_type being int, and GO_type being long long.

The mess of errors that I get when I try to compile looks like this:

/Users/jjramsey/path/to/my_tpetra_belos_code.cpp: In function 'int main(int, char**)':
/Users/jjramsey/path/to/my_tpetra_belos_code.cpp:389:40: error: no matching function for call to 'Ifpack2::Factory::create(std::string&, Teuchos::RCP<Tpetra::FECrsMatrix<double, int, long long int> >&)'
  389 |         precond = precondFactory.create(precondType, Kglobal);
      |                   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
In file included from /Users/jjramsey/spack/opt/spack/darwin-ventura-m1/gcc-12.3.0/trilinos-16.0.0-mqe2cbfudpse7y6suj3rtisuqqvyz676/include/Ifpack2_Factory.hpp:1,
                 from /Users/jjramsey/path/to/my_tpetra_belos_code.cpp:12:
/Users/jjramsey/spack/opt/spack/darwin-ventura-m1/gcc-12.3.0/trilinos-16.0.0-mqe2cbfudpse7y6suj3rtisuqqvyz676/include/Ifpack2_Factory_decl.hpp:100:3: note: candidate: 'template<class MatrixType> static Teuchos::RCP<Ifpack2::Preconditioner<typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type> > Ifpack2::Factory::create(const std::string&, const Teuchos::RCP<const T>&)'
  100 |   create (const std::string& precType,
      |   ^~~~~~
/Users/jjramsey/spack/opt/spack/darwin-ventura-m1/gcc-12.3.0/trilinos-16.0.0-mqe2cbfudpse7y6suj3rtisuqqvyz676/include/Ifpack2_Factory_decl.hpp:100:3: note:   template argument deduction/substitution failed:
/Users/jjramsey/path/to/my_tpetra_belos_code.cpp:389:40: note:   types 'const T' and 'Tpetra::FECrsMatrix<double, int, long long int>' have incompatible cv-qualifiers
  389 |         precond = precondFactory.create(precondType, Kglobal);
      |                   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/Users/jjramsey/spack/opt/spack/darwin-ventura-m1/gcc-12.3.0/trilinos-16.0.0-mqe2cbfudpse7y6suj3rtisuqqvyz676/include/Ifpack2_Factory_decl.hpp:140:3: note: candidate: 'template<class MatrixType> static Teuchos::RCP<Ifpack2::Preconditioner<typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type> > Ifpack2::Factory::create(const std::string&, const Teuchos::RCP<const T>&, int)'
  140 |   create (const std::string& precType,
      |   ^~~~~~
/Users/jjramsey/spack/opt/spack/darwin-ventura-m1/gcc-12.3.0/trilinos-16.0.0-mqe2cbfudpse7y6suj3rtisuqqvyz676/include/Ifpack2_Factory_decl.hpp:140:3: note:   template argument deduction/substitution failed:
/Users/jjramsey/path/to/my_tpetra_belos_code.cpp:389:40: note:   types 'const T' and 'Tpetra::FECrsMatrix<double, int, long long int>' have incompatible cv-qualifiers
  389 |         precond = precondFactory.create(precondType, Kglobal);
      |                   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/mkHomogPropsAndCorrGrad.dir/AEH_main.cpp.o] Error 1
make[1]: *** [src/CMakeFiles/mkHomogPropsAndCorrGrad.dir/all] Error 2

What jumps out at me from this mess is types 'const T' and 'Tpetra::FECrsMatrix<double, int, long long int>' have incompatible cv-qualifiers, as if I need a pointer to a const TpMatrix. However, the example code for Ifpack2::Factory does not indicate this.

Any idea what's going on and how I might fix it?

@trilinos/ifpack2

[cgcgcg]

You could try with

using TpetraCrs = Tpetra::CrsMatrix<Sc_type, LO_type, GO_type>;
Teuchos::RCP<Ifpack2::Preconditioner<Sc_type, LO_type, GO_type> >
        precond = precondFactory.create(precondType, Teuchos::rcp_dynamic_cast<TpCrs>(Kglobal));

[jjramsey]

Actually, what I found allowed things to at least compile was this:

Teuchos::RCP<Ifpack2::Preconditioner<Sc_type, LO_type, GO_type> >
        precond = precondFactory.create(precondType,
                                        Teuchos::rcp_implicit_cast<const TpMatrix>(Kglobal));

Again, note that the type of Kglobal was already Teuchos::RCP<TpMatrix>.