[BUG] Simple einsum program failed to compile

[lucifer1004]

The following code could not compile

#include "matx.h"

int main([[maybe_unused]] int argc, [[maybe_unused]] char **argv) {
  MATX_ENTER_HANDLER();

  auto a = matx::make_tensor<float>({10, 10});
  auto b = matx::make_tensor<float>({10, 10});
  auto c = matx::make_tensor<float>({10, 10});

  auto exec = matx::cudaExecutor();
  (c = matx::cutensor::einsum("ik,kl->il", a, b)).run(exec);
  matx::print(c);

  CUDA_CHECK_LAST_ERROR();
  MATX_EXIT_HANDLER();
}

The error message was:

MatX/include/matx/transforms/einsum.h(457): error: class "matx::detail::matxCache_t" may not have a template argument list
  static matxCache_t<EinsumParams_t<InT...>, EinsumParamsKeyHash<InT...>, EinsumParamsKeyEq<InT...>> einsum_cache;

[lucifer1004]

It seems that the code for einsum cache has not been updated according to matxCache_t's API changes.

[tmartin-gh]

Thanks! Reproduced when compiling with MATX_EN_CUTENSOR=ON. Secondary bug: compilation succeeds when using MATX_EN_CUTENSOR=OFF, but we should probably throw runtime error if MATX_EN_CUTENSOR=OFF and einsum capability not present.

[tmartin-gh]

Note: Example reproducer "ik,kl->il" is a matrix multiply, should have been caught by TYPED_TEST(EinsumTestsFloatNonComplexNonHalfTypes, GEMM).

[cliffburdick]

Fixed by 2c34e34