Compatibility with nanobind 3

[francesco-ballarin]

Hi,
nanobind 3.0.0 was released a few hours ago, and seems to have compatibility issues with islpy.

I attach below the compilation errors I get from my CI, they all seem to be related to the The None wrapper type announced in nanobind's changelog

Trimmed version of the compilation errors, post-processed by ChatGPT 5.6 Sol to avoid repetitions and highlight the relevant bits

[108/112] Building CXX object CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part3.cpp.o
FAILED: [code=1] CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part3.cpp.o

In file included from /tmp/islpy-src/src/wrapper/wrap_isl_part3.cpp:34:
/tmp/tmp3d0d7uzc/build/generated/gen-expose-part3.inc:
In function ‘void islpy_expose_part3(nanobind::module_&)’:

/tmp/tmp3d0d7uzc/build/generated/gen-expose-part3.inc:104:629:
error: no matching function for call to ‘nanobind::arg_t<>::none(bool)’

  wrap_pw_qpolynomial.def(
      "__init__",
      ...,
      py::arg("s"),
      py::arg("context").none(true)=py::none());
                         ~~~~^~~~~~

In file included from
/usr/local/lib/python3.13/dist-packages/nanobind/include/nanobind/nanobind.h:60:

/usr/local/lib/python3.13/dist-packages/nanobind/include/nanobind/nb_attr.h:50:30:
note: candidate:
‘constexpr auto nanobind::arg_t<Flags, Locked>::none() const’

  NB_INLINE constexpr auto none() const {
                           ^~~~

note: candidate expects 0 arguments, 1 provided

The same error is repeated for:
  wrap_pw_qpolynomial_fold
  wrap_union_pw_qpolynomial
  wrap_schedule
  wrap_schedule_constraints


[109/112] Building CXX object CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part2.cpp.o
FAILED: [code=1] CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part2.cpp.o

/tmp/tmp3d0d7uzc/build/generated/gen-wrap-part2.inc:12929:37:
warning: ‘isl_set* isl_set_align_divs(isl_set*)’ is deprecated

/tmp/tmp3d0d7uzc/build/generated/gen-wrap-part2.inc:22395:37:
warning: ‘isl_map* isl_map_align_divs(isl_map*)’ is deprecated

/tmp/tmp3d0d7uzc/build/generated/gen-expose-part2.inc:
In function ‘void islpy_expose_part2(nanobind::module_&)’:

/tmp/tmp3d0d7uzc/build/generated/gen-expose-part2.inc:32:594:
error: no matching function for call to ‘nanobind::arg_t<>::none(bool)’

  wrap_basic_set.def(
      "__init__",
      ...,
      py::arg("s"),
      py::arg("context").none(true)=py::none());
                         ~~~~^~~~~~

/usr/local/lib/python3.13/dist-packages/nanobind/include/nanobind/nb_attr.h:50:30:
note: candidate:
‘constexpr auto nanobind::arg_t<Flags, Locked>::none() const’

note: candidate expects 0 arguments, 1 provided

The same error is repeated for:
  wrap_basic_map
  wrap_set
  wrap_map
  wrap_union_map
  wrap_union_set


[110/112] Building CXX object CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part1.cpp.o
FAILED: [code=1] CMakeFiles/_isl.dir/src/wrapper/wrap_isl_part1.cpp.o

Warnings unrelated to the build failure:

  warning: ‘isl_space* isl_space_extend(...)’ is deprecated
  warning: ‘isl_space* isl_space_drop_inputs(...)’ is deprecated
  warning: ‘isl_space* isl_space_drop_outputs(...)’ is deprecated
  warning: ‘isl_bool isl_space_match(...)’ is deprecated

/tmp/islpy-src/src/wrapper/wrap_isl_part1.cpp:
In function ‘void islpy_expose_part1(nanobind::module_&)’:

/tmp/islpy-src/src/wrapper/wrap_isl_part1.cpp:104:47:
error: no matching function for call to ‘nanobind::arg_t<>::none(bool)’

  }, py::arg("i"), py::arg("context").none(true)=py::none()
                                            ^

/usr/local/lib/python3.13/dist-packages/nanobind/include/nanobind/nb_attr.h:50:30:
note: candidate:
‘constexpr auto nanobind::arg_t<Flags, Locked>::none() const’

note: candidate expects 0 arguments, 1 provided

/tmp/islpy-src/src/wrapper/wrap_isl_part1.cpp:154:27:
error: no matching function for call to ‘nanobind::arg_t<>::none(bool)’

  py::arg("user").none(true)=py::none(),
                  ~~~~^~~~~~

/tmp/islpy-src/src/wrapper/wrap_isl_part1.cpp:155:30:
error: no matching function for call to ‘nanobind::arg_t<>::none(bool)’

  py::arg("context").none(true)=py::none()
                     ~~~~^~~~~~

The same error is repeated in generated bindings for:
  wrap_id_list
  wrap_val_list
  wrap_set_list
  wrap_map_list
  wrap_aff_list
  wrap_pw_aff_list
  wrap_pw_multi_aff_list
  wrap_union_pw_aff_list
  wrap_union_set_list
  wrap_val
  wrap_multi_val
  wrap_aff
  wrap_pw_aff
  wrap_union_pw_aff
  wrap_multi_aff
  wrap_multi_pw_aff
  wrap_pw_multi_aff
  wrap_union_pw_multi_aff
  wrap_multi_union_pw_aff
  wrap_id
  wrap_multi_id
  wrap_space

All report:

  error: no matching function for call to
  ‘nanobind::arg_t<>::none(bool)’

with nanobind providing only:

  constexpr auto none() const

and therefore:

  candidate expects 0 arguments, 1 provided


ninja: build stopped: subcommand failed.

*** CMake build failed
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for islpy
Failed to build islpy