Failing to wrap nda::basic_array<> when upgrading nda/1.3.x from 35a5a2e to 39f6e14

[HugoStrand]

Dear cpp2py developers,

I have a Triqs application with c++ code wrapped by cpp2py. Today rebuilding Triqs the c++/python wrapping stopped compiling. I have narrowed down the error as stemming from a change of nda/1.3.x at commit 35a5a2e to current latest commit 39f6e14.

If I manually checkout nda/1.3.x at 35a5a2e in my cmake directory ./deps/nda_src and rebuild and install Triqs, my application compiles again.

The compilation error message is:

[ 14%] Generating impurity_wrap.cxx
[ 18%] Building CXX object python/fastdiag/CMakeFiles/impurity.dir/impurity_wrap.cxx.o
In file included from /.../dev/ppsc-soe/cbuild/python/fastdiag/impurity_wrap.cxx:39:
/.../apps/cppdlr/include/nda_py/cpp2py_converters.hpp:94:75: error: type/value mismatch at argument 5 in template parameter list for 'template<class ValueType, int Rank, class Layout, char Algebra, class ContainerPolicy> class nda::basic_array'
   94 |   struct py_converter<nda::basic_array<T, R, nda::C_layout, Algebra, nda::heap>> {
      |                                                                           ^~~~
/.../apps/cppdlr/include/nda_py/cpp2py_converters.hpp:94:75: note:   expected a type, got 'heap'
/.../apps/cppdlr/include/nda_py/cpp2py_converters.hpp:94:79: error: template argument 1 is invalid
   94 |   struct py_converter<nda::basic_array<T, R, nda::C_layout, Algebra, nda::heap>> {
      |                                                                               ^~
make[2]: *** [python/fastdiag/CMakeFiles/impurity.dir/impurity_wrap.cxx.o] Error 1
make[1]: *** [python/fastdiag/CMakeFiles/impurity.dir/all] Error 2

Looking at nda it seems like the nda::heap nowadays needs a template argument, like nda::heap<mem::Host>, which is missing in the generated wrapper code impurity_wrap.cxx.

Where does the py_converters for nda::basic_array live? cpp2py or nda?

Where should one start digging to try to solve this issue.

Best regards,
Hugo

[Wentzell]

Dear @HugoStrand,

The heap storage policy has been a templated alias since nda 1.2.x, c.f. https://github.com/TRIQS/nda/blob/baa84b2e298511ce45c68271a6c8660fa6386843/c%2B%2B/nda/mem/policies.hpp#L41-L43

Is it possible that your *_desc.py file that generates the bindings in your project still contains the non-templated syntax?
If so, can you update any occurances of nda::heap to nda::heap<>, and try again?