updating CHAI to c++20

.gitignore

@@ -17,3 +17,4 @@ Win32/x64/
 *.orig
 *.code-workspace
 slirp.out
+.codex

CMakeLists.txt

@@ -29,12 +29,13 @@ message(STATUS "Using CMake version ${CMAKE_VERSION}")
 ################################
 # BLT
 ################################
-set(BLT_CXX_STD c++17 CACHE STRING "")
+set(BLT_CXX_STD c++20 CACHE STRING "")
 
 if(("${BLT_CXX_STD}" STREQUAL "c++98") OR
    ("${BLT_CXX_STD}" STREQUAL "c++11") OR
-   ("${BLT_CXX_STD}" STREQUAL "c++14"))
-   message(FATAL_ERROR "CHAI requires a minimum C++ standard of c++17. Please set BLT_CXX_STD appropriately.")
+   ("${BLT_CXX_STD}" STREQUAL "c++14") OR
+   ("${BLT_CXX_STD}" STREQUAL "c++17"))
+   message(FATAL_ERROR "CHAI requires a minimum C++ standard of c++20. Please set BLT_CXX_STD appropriately.")
 endif()
 
 if (NOT BLT_LOADED)

Dockerfile

@@ -5,7 +5,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 ##############################################################################
 
-FROM ghcr.io/llnl/radiuss:ubuntu-22.04-gcc-13 AS gcc
+FROM ghcr.io/llnl/radiuss:ubuntu-24.04-gcc-13 AS gcc
 ENV GTEST_COLOR=1
 COPY . /home/chai/workspace
 WORKDIR /home/chai/workspace/build

RELEASE_NOTES.md

@@ -12,6 +12,12 @@ in this file.
 
 The format of this file is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
+## [Unreleased] = Release date yyyy-mm-dd
+
+### Changed
+- CHAI now requires C++20 as the minimum C++ standard.
+- CHAI now requires CUDA 12 as the minimum CUDA version.
+
 ## [Version 2025.12.0] = Release date 2025-12-22
 
 ### Fixed

tests/integration/managed_ptr_tests.cpp

@@ -6,6 +6,8 @@
 //////////////////////////////////////////////////////////////////////////////
 #include "gtest/gtest.h"
 
+#define CHAI_USE_VAR(x) static_cast<void>(x)
+
 #define GPU_TEST(X, Y)              \
   static void gpu_test_##X##Y();    \
   TEST(X, Y) { gpu_test_##X##Y(); } \
@@ -872,6 +874,8 @@ class ABase {
    // Virtual function to manipulate an array of objects
    CHAI_HOST_DEVICE virtual void setArrayValues(int size, int value) {
       // Base implementation does nothing
+      CHAI_USE_VAR(size);
+      CHAI_USE_VAR(value);
    }
 
    CHAI_HOST_DEVICE virtual int getTypeID() const { return 0; }
@@ -919,6 +923,7 @@ TEST(managed_ptr, polymorphic_with_ManagedArray_unpacker)
    // Use virtual function to modify array through the member pointer
    const int base_value = 10;
    forall( sequential(), 0, 1,[=](int i ) {
+      CHAI_USE_VAR(i);
       poly_ptr->setArrayValues(size, base_value);
    });