Raise minimum C++ standard to 20

.github/workflows/builds.yml

@@ -25,48 +25,33 @@ jobs:
       matrix:
         platform:
           - name: CPU
-            container: ghcr.io/acts-project/ubuntu2004:v30
-            cxx_standard: "17"
-            options:
-            run_tests: true
-          - name: CPU
-            container: ghcr.io/acts-project/ubuntu2004:v30
-            cxx_standard: "17"
-            options: -DTRACCC_USE_ROOT=FALSE
-            run_tests: true
-          - name: CPU
-            container: ghcr.io/acts-project/ubuntu2404:48
+            container: ghcr.io/acts-project/ubuntu2404:56
             cxx_standard: "20"
-            options: -DTRACCC_USE_ROOT=FALSE -DTRACCC_ENFORCE_CONCEPTS=TRUE
+            options:
             run_tests: true
           - name: HIP
-            container: ghcr.io/acts-project/ubuntu2004_rocm:47
-            cxx_standard: "17"
+            container: ghcr.io/acts-project/ubuntu2204_rocm_clang_cxx20:56
+            cxx_standard: "20"
             options: -DTRACCC_BUILD_HIP=TRUE -DTRACCC_SETUP_ROCTHRUST=TRUE
             run_tests: false
           - name: CUDA
-            container: ghcr.io/acts-project/ubuntu2004_cuda:47
-            cxx_standard: "17"
-            options: -DTRACCC_BUILD_CUDA=TRUE -DTRACCC_ENABLE_NVTX_PROFILING=TRUE
-            run_tests: false
-          - name: CUDA
-            container: ghcr.io/acts-project/ubuntu2204_cuda:48
+            container: ghcr.io/acts-project/ubuntu2404_cuda:56
             cxx_standard: "20"
-            options: -DTRACCC_BUILD_CUDA=TRUE -DTRACCC_USE_ROOT=FALSE -DTRACCC_ENFORCE_CONCEPTS=TRUE -DCMAKE_CUDA_FLAGS="-std=c++20"
+            options: -DTRACCC_BUILD_CUDA=TRUE -DCMAKE_CUDA_FLAGS="-std=c++20"
             run_tests: false
           - name: SYCL
-            container: ghcr.io/acts-project/ubuntu2004_oneapi:47
-            cxx_standard: "17"
-            options: -DTRACCC_BUILD_SYCL=TRUE
+            container: ghcr.io/acts-project/ubuntu2404_oneapi:56
+            cxx_standard: "20"
+            options: -DTRACCC_BUILD_SYCL=TRUE -DCMAKE_SYCL_FLAGS="-fsycl -fsycl-targets=spir64"
             run_tests: true
           - name: KOKKOS
-            container: ghcr.io/acts-project/ubuntu2004:v30
-            cxx_standard: "17"
+            container: ghcr.io/acts-project/ubuntu2404:56
+            cxx_standard: "20"
             options: -DTRACCC_BUILD_KOKKOS=TRUE
             run_tests: false
           - name: ALPAKA
-            container: ghcr.io/acts-project/ubuntu2204:v33
-            cxx_standard: "17"
+            container: ghcr.io/acts-project/ubuntu2404:56
+            cxx_standard: "20"
             options: -DTRACCC_BUILD_ALPAKA=TRUE
             run_tests: false
         build:
@@ -75,14 +60,14 @@ jobs:
         include:
           - platform:
               name: "SYCL"
-              container: ghcr.io/acts-project/ubuntu2004_cuda_oneapi:47
-              cxx_standard: "17"
+              container: ghcr.io/acts-project/ubuntu2404_cuda_oneapi:56
+              cxx_standard: "20"
               options: -DTRACCC_BUILD_SYCL=TRUE -DTRACCC_BUILD_CUDA=FALSE -DVECMEM_BUILD_CUDA_LIBRARY=FALSE
             build: Release
           - platform:
               name: "SYCL"
-              container: ghcr.io/acts-project/ubuntu2004_rocm_oneapi:47
-              cxx_standard: "17"
+              container: ghcr.io/acts-project/ubuntu2404_rocm_oneapi:56
+              cxx_standard: "20"
               options: -DTRACCC_BUILD_SYCL=TRUE -DVECMEM_BUILD_HIP_LIBRARY=FALSE
             build: Release
     # Use BASH as the shell from the images.

.gitlab-ci.yml

@@ -25,7 +25,8 @@ stages:
     paths:
       - build
   script:
-    - cmake -G Ninja --preset ${TRACCC_BUILD_PRESET} -DCMAKE_BUILD_TYPE=Release
+    - SYCLFLAGS="${TRACCC_SYCL_FLAGS}" CXXFLAGS="${TRACCC_CXX_FLAGS}"
+      cmake -G Ninja --preset ${TRACCC_BUILD_PRESET} -DCMAKE_BUILD_TYPE=Release
       -DTRACCC_BUILD_EXAMPLES=FALSE ${TRACCC_CMAKE_ARGS}
       -S src -B build
     - cmake --build build --parallel 2
@@ -52,15 +53,15 @@ stages:
 # CUDA build job.
 build:cuda:
   <<: *build_job
-  image: ghcr.io/acts-project/ubuntu2004_cuda:47
+  image: ghcr.io/acts-project/ubuntu2204_cuda:56
   variables:
     TRACCC_BUILD_TYPE: CUDA
     TRACCC_BUILD_PRESET: cuda
 
 # CUDA test job.
 test:cuda:
   <<: *nvidia_test_job
-  image: ghcr.io/acts-project/ubuntu2004_cuda:47
+  image: ghcr.io/acts-project/ubuntu2204_cuda:56
   variables:
     TRACCC_BUILD_TYPE: CUDA
   dependencies:
@@ -69,15 +70,17 @@ test:cuda:
 # SYCL build job (with an Intel backend).
 build:sycl_intel:
   <<: *build_job
-  image: ghcr.io/acts-project/ubuntu2004_oneapi:47
+  image: ghcr.io/acts-project/ubuntu2404_oneapi:56
   variables:
     TRACCC_BUILD_TYPE: SYCL
     TRACCC_BUILD_PRESET: sycl
+    TRACCC_SYCL_FLAGS: -fsycl -fsycl-targets=spir64
+    TRACCC_CMAKE_ARGS: -DTRACCC_BUILD_CUDA=FALSE
 
 # SYCL test job (with an Intel backend).
 test:sycl_intel:
   <<: *intel_test_job
-  image: ghcr.io/acts-project/ubuntu2004_oneapi:47
+  image: ghcr.io/acts-project/ubuntu2404_oneapi:56
   variables:
     TRACCC_BUILD_TYPE: SYCL
     ONEAPI_DEVICE_SELECTOR: opencl:*
@@ -87,16 +90,18 @@ test:sycl_intel:
 # SYCL build job (with an NVIDIA backend).
 build:sycl_nvidia:
   <<: *build_job
-  image: ghcr.io/acts-project/ubuntu2004_cuda_oneapi:48
+  image: ghcr.io/acts-project/ubuntu2204_cuda_oneapi:56
   variables:
     TRACCC_BUILD_TYPE: SYCL
     TRACCC_BUILD_PRESET: sycl
+    TRACCC_SYCL_FLAGS: -fsycl -fsycl-targets=nvidia_gpu_sm_75 -Wno-unknown-cuda-version -Wno-deprecated-declarations
+    TRACCC_CXX_FLAGS: -Wno-deprecated-declarations
     TRACCC_CMAKE_ARGS: -DTRACCC_BUILD_CUDA=FALSE
 
 # SYCL test job (with an NVIDIA backend).
 test:sycl_nvidia:
   <<: *nvidia_test_job
-  image: ghcr.io/acts-project/ubuntu2004_cuda_oneapi:48
+  image: ghcr.io/acts-project/ubuntu2204_cuda_oneapi:56
   variables:
     TRACCC_BUILD_TYPE: SYCL
     ONEAPI_DEVICE_SELECTOR: cuda:*

CMakeLists.txt

@@ -9,12 +9,16 @@ cmake_minimum_required( VERSION 3.9 )
 project( traccc VERSION 0.12.0 LANGUAGES CXX )
 
 # Set up the used C++ standard(s).
-set( CMAKE_CXX_STANDARD 17 CACHE STRING "The (host) C++ standard to use" )
+set( CMAKE_CXX_STANDARD 20 CACHE STRING "The (host) C++ standard to use" )
 set( CMAKE_CXX_EXTENSIONS FALSE CACHE BOOL "Disable (host) C++ extensions" )
-set( CMAKE_CUDA_STANDARD 17 CACHE STRING "The (CUDA) C++ standard to use" )
+set( CMAKE_CUDA_STANDARD 20 CACHE STRING "The (CUDA) C++ standard to use" )
 set( CMAKE_CUDA_EXTENSIONS FALSE CACHE BOOL "Disable (CUDA) C++ extensions" )
-set( CMAKE_SYCL_STANDARD 17 CACHE STRING "The (SYCL) C++ standard to use" )
-set( CMAKE_HIP_STANDARD 17 CACHE STRING "The (HIP) C++ standard to use" )
+set( CMAKE_SYCL_STANDARD 20 CACHE STRING "The (SYCL) C++ standard to use" )
+set( CMAKE_HIP_STANDARD 20 CACHE STRING "The (HIP) C++ standard to use" )
+
+if(${CMAKE_CXX_STANDARD} LESS 20)
+   message(SEND_ERROR "CMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}, but traccc requires C++>=20")
+endif()
 
 # Flag controlling whether warnings should make the build fail.
 option( TRACCC_FAIL_ON_WARNINGS
@@ -67,12 +71,22 @@ option( TRACCC_BUILD_EXAMPLES "Build the examples of traccc" TRUE )
 option( TRACCC_USE_SYSTEM_LIBS "Use system libraries be default" FALSE )
 option( TRACCC_USE_ROOT "Use ROOT in the build (if needed)" TRUE )
 
-# Flag enforcing concept usage.
-option( TRACCC_ENFORCE_CONCEPTS "Throw an error if concepts are not available" FALSE )
-
 # Clean up.
 unset( TRACCC_BUILD_CUDA_DEFAULT )
 
+# Check CUDA and SYCL C++ standards
+if(${TRACCC_BUILD_CUDA} AND ${CMAKE_CUDA_STANDARD} LESS 20)
+   message(SEND_ERROR "CMAKE_CUDA_STANDARD=${CMAKE_CUDA_STANDARD}, but traccc requires C++>=20")
+endif()
+
+if(${TRACCC_BUILD_SYCL} AND ${CMAKE_SYCL_STANDARD} LESS 20)
+   message(SEND_ERROR "CMAKE_SYCL_STANDARD=${CMAKE_SYCL_STANDARD}, but traccc requires C++>=20")
+endif()
+
+if(${TRACCC_BUILD_HIP} AND ${CMAKE_HIP_STANDARD} LESS 20)
+   message(SEND_ERROR "CMAKE_HIP_STANDARD=${CMAKE_HIP_STANDARD}, but traccc requires C++>=20")
+endif()
+
 # Set up VecMem.
 option( TRACCC_SETUP_VECMEM
    "Set up the VecMem target(s) explicitly" TRUE )

core/CMakeLists.txt

@@ -110,11 +110,3 @@ target_link_libraries( traccc_core
 # CUDA or HIP backend with SYCL.
 target_compile_definitions( traccc_core
   PUBLIC $<$<COMPILE_LANGUAGE:SYCL>:EIGEN_NO_CUDA EIGEN_NO_HIP> )
-
-if ( TRACCC_ENFORCE_CONCEPTS )
-  target_compile_definitions(
-    traccc_core
-    PUBLIC
-    TRACCC_ENFORCE_CONCEPTS
-  )
-endif ()

core/include/traccc/sanity/contiguous_on.hpp

@@ -8,9 +8,6 @@
 
 #pragma once
 
-// Project include(s).
-#include "traccc/definitions/concepts.hpp"
-
 // VecMem include(s).
 #include <memory>
 #include <vecmem/containers/data/vector_view.hpp>
@@ -19,9 +16,7 @@
 #include <vecmem/utils/copy.hpp>
 
 // System include
-#if __cpp_concepts >= 201907L
 #include <concepts>
-#endif
 #include <memory>
 #include <unordered_set>
 
@@ -44,12 +39,9 @@ namespace traccc::host {
  * @return true If the vector is contiguous on `P`.
  * @return false Otherwise.
  */
-template <TRACCC_CONSTRAINT(std::semiregular) P,
-          TRACCC_CONSTRAINT(std::equality_comparable) T>
-#if __cpp_concepts >= 201907L
-requires std::regular_invocable<P, T>
-#endif
-    bool is_contiguous_on(P&& projection, vecmem::data::vector_view<T> vector) {
+template <std::semiregular P, std::equality_comparable T>
+requires std::regular_invocable<P, T> bool is_contiguous_on(
+    P&& projection, vecmem::data::vector_view<T> vector) {
     // Grab the number of elements in our vector.
     uint32_t n = vector.size();
 

core/include/traccc/sanity/ordered_on.hpp

@@ -8,19 +8,14 @@
 
 #pragma once
 
-// Project include(s).
-#include "traccc/definitions/concepts.hpp"
-
 // VecMem include(s).
 #include <vecmem/containers/data/vector_view.hpp>
 #include <vecmem/containers/device_vector.hpp>
 #include <vecmem/memory/memory_resource.hpp>
 #include <vecmem/utils/copy.hpp>
 
 // System include
-#if __cpp_concepts >= 201907L
 #include <concepts>
-#endif
 
 namespace traccc::host {
 /**
@@ -46,11 +41,9 @@ namespace traccc::host {
  * @return true If the vector is ordered on `R`.
  * @return false Otherwise.
  */
-template <TRACCC_CONSTRAINT(std::semiregular) R, typename T>
-#if __cpp_concepts >= 201907L
-requires std::relation<R, T, T>
-#endif
-    bool is_ordered_on(R relation, vecmem::data::vector_view<T> vector) {
+template <std::semiregular R, typename T>
+requires std::relation<R, T, T> bool is_ordered_on(
+    R relation, vecmem::data::vector_view<T> vector) {
     // Grab the number of elements in our vector.
     uint32_t n = vector.size();
 

device/common/include/traccc/clusterization/device/ccl_kernel.hpp

@@ -87,7 +87,7 @@ struct ccl_kernel_helper {
 /// @param[out] measurements_view collection of measurements
 /// @param[out] cell_links    collection of links to measurements each cell is
 /// put into
-template <TRACCC_CONSTRAINT(device::concepts::barrier) barrier_t>
+template <device::concepts::barrier barrier_t>
 TRACCC_DEVICE inline void ccl_kernel(
     details::index_t threadId, details::index_t blckDim, unsigned int blockId,
     const cell_collection_types::const_view cells_view,

device/common/include/traccc/clusterization/device/impl/ccl_kernel.ipp

@@ -32,7 +32,7 @@ namespace traccc::device {
 ///                     iteration.
 /// @param[in] barrier  A generic object for block-wide synchronisation
 ///
-template <TRACCC_CONSTRAINT(device::concepts::barrier) barrier_t>
+template <device::concepts::barrier barrier_t>
 TRACCC_DEVICE void fast_sv_1(
     vecmem::device_vector<details::index_t>& f,
     vecmem::device_vector<details::index_t>& gf,
@@ -125,7 +125,7 @@ TRACCC_DEVICE void fast_sv_1(
     } while (barrier.blockOr(gf_changed));
 }
 
-template <TRACCC_CONSTRAINT(device::concepts::barrier) barrier_t>
+template <device::concepts::barrier barrier_t>
 TRACCC_DEVICE inline void ccl_kernel(
     const details::index_t threadId, const details::index_t blckDim,
     const unsigned int blockId,

device/common/include/traccc/device/concepts/barrier.hpp

@@ -8,14 +8,9 @@
 
 #pragma once
 
-#include "traccc/definitions/concepts.hpp"
-
-#if __cpp_concepts >= 201907L
 #include <concepts>
-#endif
 
 namespace traccc::device::concepts {
-#if __cpp_concepts >= 201907L
 /**
  * @brief Concept to ensure that a type is barrier-like, i.e. it can
  * synchronize threads in a compute block.
@@ -57,5 +52,4 @@ concept barrier = requires(T& b) {
         ->std::integral;
     };
 };
-#endif
 }  // namespace traccc::device::concepts

device/common/include/traccc/seeding/device/impl/select_seeds.ipp

@@ -153,13 +153,13 @@ inline void select_seeds(
                 scalar seed1_sum = 0;
                 scalar seed2_sum = 0;
 
-                const internal_spacepoint<spacepoint>& ispB1 =
+                const internal_spacepoint<spacepoint> ispB1 =
                     internal_sp_device.bin(lhs.sp1.bin_idx)[lhs.sp1.sp_idx];
-                const internal_spacepoint<spacepoint>& ispT1 =
+                const internal_spacepoint<spacepoint> ispT1 =
                     internal_sp_device.bin(lhs.sp3.bin_idx)[lhs.sp3.sp_idx];
-                const internal_spacepoint<spacepoint>& ispB2 =
+                const internal_spacepoint<spacepoint> ispB2 =
                     internal_sp_device.bin(rhs.sp1.bin_idx)[rhs.sp1.sp_idx];
-                const internal_spacepoint<spacepoint>& ispT2 =
+                const internal_spacepoint<spacepoint> ispT2 =
                     internal_sp_device.bin(rhs.sp3.bin_idx)[rhs.sp3.sp_idx];
 
                 const spacepoint& spB1 = spacepoints_device.at(ispB1.m_link);
@@ -185,9 +185,9 @@ inline void select_seeds(
         const triplet& aTriplet = data[i];
         const sp_location& spB_loc = aTriplet.sp1;
         const sp_location& spT_loc = aTriplet.sp3;
-        const internal_spacepoint<spacepoint>& spB =
+        const internal_spacepoint<spacepoint> spB =
             internal_sp_device.bin(spB_loc.bin_idx)[spB_loc.sp_idx];
-        const internal_spacepoint<spacepoint>& spT =
+        const internal_spacepoint<spacepoint> spT =
             internal_sp_device.bin(spT_loc.bin_idx)[spT_loc.sp_idx];
 
         // if the number of seeds reaches the threshold, break