use cuda tag and let cmake use other backends

example/useCuBLASInAlpaka/CMakeLists.txt

@@ -17,13 +17,6 @@ set(_TARGET_NAME useCuBLASInAlpaka)
 
 project(${_TARGET_NAME} LANGUAGES CXX)
 
-# Check if the cmake variables to see if the Acc option is Cuda Only.
-if(NOT alpaka_ACC_GPU_CUDA_ONLY_MODE)
-    # Print a warning and skip target creation
-    message(WARNING "Skipping build of 'useCuBLASInAlpaka' because alpaka_ACC_GPU_CUDA_ONLY_MODE is not enabled.")
-    return()
-endif()
-
 # Add cuBLAS library
 find_package(CUDA REQUIRED)
 set(CUDA_LIBRARIES ${CUDA_LIBRARIES} cublas)

example/useCuBLASInAlpaka/src/useCuBLASInAlpaka.cpp

@@ -32,12 +32,7 @@ void initializeMatrix(DataType* buffer, Idx rows, Idx cols)
     }
 }
 
-// In standard projects, you typically do not execute the code with any available accelerator.
-// Instead, a single accelerator is selected once from the active accelerators and the kernels are executed with the
-// selected accelerator only. If you use the example as the starting point for your project, you can rename the
-// example() function to main() and move the accelerator tag to the function body.
-template<alpaka::concepts::Tag TAccTag>
-auto example(TAccTag const&) -> int
+auto main() -> int
 {
     using Dim1D = alpaka::DimInt<1>;
 
@@ -48,7 +43,7 @@ auto example(TAccTag const&) -> int
 
     // Define the accelerator and queue
     // Use Cuda Accelerator. Cmake Acc flags should be set to Cuda-Only
-    using Acc = alpaka::TagToAcc<TAccTag, Dim1D, Idx>;
+    using Acc = alpaka::TagToAcc<alpaka::TagGpuCudaRt, Dim1D, Idx>;
     using Queue = alpaka::Queue<Acc, alpaka::Blocking>;
 
     auto const platformHost = alpaka::PlatformCpu{};
@@ -182,21 +177,3 @@ auto example(TAccTag const&) -> int
     cublasDestroy(cublasHandle);
     return EXIT_SUCCESS;
 }
-
-auto main() -> int
-{
-    std::cout << "Check enabled accelerator tags:" << std::endl;
-    alpaka::printTagNames<alpaka::EnabledAccTags>();
-    // Execute the example once for each enabled accelerator.
-    // If you would like to execute it for a single accelerator only you can use the following code.
-    //  \code{.cpp}
-    //  auto tag = TagCpuSerial;
-    //  return example(tag);
-    //  \endcode
-    //
-    // valid tags:
-    //   TagCpuSerial, TagGpuHipRt, TagGpuCudaRt, TagCpuOmp2Blocks, TagCpuTbbBlocks,
-    //   TagCpuOmp2Threads, TagCpuSycl, TagCpuTbbBlocks, TagCpuThreads,
-    //   TagFpgaSyclIntel, TagGenericSycl, TagGpuSyclIntel
-    return alpaka::executeForEachAccTag([=](auto const& tag) { return example(tag); });
-}