Very strange bug in test_parameter.cpp

[evanberkowitz]

I'm compiling with

> /usr/bin/clang --version
Apple clang version 16.0.0 (clang-1600.0.26.3)
Target: arm64-apple-darwin23.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

and am getting

[ 98%] Building CXX object Tests/CMakeFiles/test_parameter.dir/Parameter/test_parameter.cpp.o
In file included from /Users/evanberkowitz/physics/hubbard/nsl/Tests/Parameter/test_parameter.cpp:1:
In file included from /Users/evanberkowitz/physics/hubbard/nsl/Tests/Parameter/../test.hpp:5:
In file included from /Users/evanberkowitz/physics/hubbard/nsl/src/NSL/NSL.hpp:11:
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/typePromotion.hpp:44:33: error: invalid reference to function 'deduce': constraints not satisfied
   44 |     using CommonType = decltype(deduce());
      |                                 ^
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/typePromotion.hpp:110:1: note: in instantiation of template class 'NSL::TypePromotion<std::string, double>' requested here
  110 | using CommonTypeOf = typename TypePromotion<TypeLeft,TypeRight>::CommonType;
      | ^
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/Tensor/Impl/operatorMultiplication.tpp:33:25: note: in instantiation of template type alias 'CommonTypeOf' requested here
   33 | inline NSL::Tensor<NSL::CommonTypeOf<ValueType,TensorType>> operator*(const ValueType & value, const NSL::Tensor<TensorType> & tensor) {
      |                         ^
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:125:9: note: while substituting deduced template arguments into function template 'operator*' [with ValueType = std::string, TensorType = double]
  125 |     { t * u } -> std::convertible_to<decltype(t * u)>;
      |         ^
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:125:7: note: in instantiation of requirement here
  125 |     { t * u } -> std::convertible_to<decltype(t * u)>;
      |       ^~~~~
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:124:27: note: while substituting template arguments into constraint expression here
  124 | concept areMultipliable = requires(T t, U u) {
      |                           ^~~~~~~~~~~~~~~~~~~~
  125 |     { t * u } -> std::convertible_to<decltype(t * u)>;
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  126 | };
      | ~
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:603:40: note: (skipping 36 contexts in backtrace; use -ftemplate-backtrace-limit=0 to see all)
  603 |                         if constexpr ( areMultipliable<decltype(lhs_arg),decltype(rhs_arg)> ){
      |                                        ^
/Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:599:21: note: in instantiation of function template specialization 'std::visit<(lambda at /Users/evanberkowitz/physics/hubbard/nsl/src/NSL/parameter.tpp:600:13), std::variant<bool, int, long long, float, double, c10::complex<float>, c10::complex<double>, std::string, NSL::Tensor<double>, NSL::Tensor<c10::complex<double>>, std::vector<std::vector<double>>, NSL::Device> &, void>' requested here
  599 |         return std::visit(
      |                     ^
/Users/evanberkowitz/physics/hubbard/nsl/Tests/Parameter/test_parameter.cpp:14:52: note: in instantiation of member function 'NSL::GeneralType<bool, int, long long, float, double, c10::complex<float>, c10::complex<double>, std::string, NSL::Tensor<double>, NSL::Tensor<c10::complex<double>>, std::vector<std::vector<double>>, NSL::Device>::operator*' requested here
   14 |     REQUIRE_NOTHROW(params["key4"] = params["key3"]*params["key2"]);
      |                                                    ^
/Users/evanberkowitz/physics/hubbard/nsl/Tests/Parameter/test_parameter.cpp:3:1: note: in instantiation of function template specialization 'C_A_T_C_H_T_E_M_P_L_A_T_E_T_E_S_T_F_U_N_C_2<int>' requested here
    3 | NSL_TEST_CASE("Parameter", "[Parameter]"){
      | ^
/Users/evanberkowitz/physics/hubbard/nsl/Tests/Parameter/../test.hpp:45:31: note: expanded from macro 'NSL_TEST_CASE'
   45 | #define NSL_TEST_CASE(_1, _2) TEMPLATE_TEST_CASE(_1, _2, NSL_TYPES)
      |                               ^

after which it traces back into zillions of lines of catch2 errors.