specify standard C++ in CMake files

Author: jiriklepl

examples/matrix/CMakeLists.txt

@@ -2,11 +2,12 @@ cmake_minimum_required(VERSION 3.10)
 Include(FetchContent)
 
 # set the project name
-project(NoarrStructuresMatrixExample VERSION 0.1)
+project(NoarrStructuresMatrixExample VERSION 0.1 LANGUAGES CXX)
 
 # specify the C++ standard
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 # setup the test runner executable
 add_executable(matrix matrix.cpp)

tests/CMakeLists.txt

@@ -1,7 +1,11 @@
 cmake_minimum_required(VERSION 3.10)
 
 # set the project name
-project(NoarrTests VERSION 0.20.0)
+project(
+  NoarrTests VERSION 0.20.0
+  DESCRIPTION "Tests for the Noarr library"
+  LANGUAGES CXX
+)
 
 include(CTest)
 enable_testing()