Default to C++11

CMakeLists.txt

@@ -53,6 +53,8 @@ set(EXE_NAME babelstream)
 
 # select default build type
 set(CMAKE_BUILD_TYPE "Release")
+# for chrono and some basic CXX features, models can overwrite this if required
+set(CMAKE_CXX_STANDARD 11)
 
 if (NOT CMAKE_BUILD_TYPE)
     message("No CMAKE_BUILD_TYPE specified, defaulting to 'Release'")

KOKKOS.cmake

@@ -17,6 +17,7 @@ set(KOKKOS_FLAGS_CPU_INTEL -qopt-streaming-stores=always)
 
 macro(setup)
 
+    set(CMAKE_CXX_STANDARD 14)
     cmake_policy(SET CMP0074 NEW) #see https://github.com/kokkos/kokkos/blob/master/BUILD.md
 
     message(STATUS "Building using in-tree Kokkos source at `${KOKKOS_IN_TREE}`")

STD20.cmake

@@ -10,6 +10,7 @@ macro(setup)
     # C++ 2a is too new, disable CMake's std flags completely:
     set(CMAKE_CXX_EXTENSIONS OFF)
     set(CMAKE_CXX_STANDARD_REQUIRED OFF)
+    unset(CMAKE_CXX_STANDARD) # drop any existing standard we have set by default
     # and append our own:
     register_append_cxx_flags(ANY -std=c++2a)
 endmacro()