Compiling on Octave 10 (dev):

/usr/local/bin/mkoctfile-10.0.0 --verbose -c low_level_functions.cc
g++ -std=gnu++17 -c  -fPIC -I/usr/local/include/octave-10.0.0/octave/.. -I/usr/local/include/octave-10.0.0/octave -I/usr/local/include  -pthread -fopenmp -ggdb3 -O2 -march=native -mtune=native -mavx -mavx2 -flto=auto    low_level_functions.cc -o low_level_functions.o
low_level_functions.cc: In function ‘int surfderivcpts(octave_idx_type, octave_idx_type, const RowVector&, octave_idx_type, octave_idx_type, const RowVector&, const Matrix&, octave_idx_type, octave_idx_type, octave_idx_type, octave_idx_type, octave_idx_type, NDArray&)’:
low_level_functions.cc:292:15: error: ‘assert’ was not declared in this scope
  292 |               assert (k<idxa(0) && i<idxa(2) && j-s1<idxa(3));
      |               ^~~~~~
low_level_functions.cc:23:1: note: ‘assert’ is defined in header ‘<cassert>’; did you forget to ‘#include <cassert>’?
   22 | #include <iostream>
  +++ |+#include <cassert>
   23 |
low_level_functions.cc:320:19: error: ‘assert’ was not declared in this scope
  320 |                   assert (k<idxa(0) && l<idxa(1)
      |                   ^~~~~~
low_level_functions.cc:320:19: note: ‘assert’ is defined in header ‘<cassert>’; did you forget to ‘#include <cassert>’?
make: *** [Makefile:34: low_level_functions.o] Error 1
make: Leaving directory '/tmp/oct-blKnTZ/nurbs-1.4.3/src'

The mxe-octave patch is:
https://hg.octave.org/mxe-octave/rev/ebdff9919577

Discussion:

https://octave.discourse.group/t/assert-panic-error-and-ndebug/5409/20

Dmitri.
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