I googled RAJA and found it was a HPC (High performance computing) library for running GPU code in C++. This couldn't be that bad, right? Turns out I was terribly wrong.

Behold, I present you this fucking monstrosity (Directly from the RAJA matrix multiplication tutorial):

  using EXEC_POL9 =
    RAJA::KernelPolicy<
      RAJA::statement::CudaKernel<
        RAJA::statement::Tile<1, RAJA::statement::tile_fixed<CUDA_BLOCK_SIZE>, RAJA::cuda_block_y_loop,
          RAJA::statement::Tile<0, RAJA::statement::tile_fixed<CUDA_BLOCK_SIZE>, RAJA::cuda_block_x_loop,
            RAJA::statement::For<1, RAJA::cuda_thread_y_loop, // row
              RAJA::statement::For<0, RAJA::cuda_thread_x_loop, // col
                RAJA::statement::Lambda<0>,   // dot = 0.0
                RAJA::statement::For<2, RAJA::seq_exec,
                    RAJA::statement::Lambda<1> // dot += ...
                >,
                RAJA::statement::Lambda<2>   // set C = ...
              >
            >
          >
        >
      >
    >;

And that's just for matrix multiplication. I cannot imagine how fucking terrifying it will to write something more complicated than that. If I were to write (and debug) this mindfucking mess of templated code, I would rather escape this trainwreck and go back to writing CUDA/OpenCL code...