Update CXX_STANDARD from 14 to 17

Author: Dominic Price

CMakeLists.txt

@@ -2,7 +2,12 @@ set(CMAKE_LEGACY_CYGWIN_WIN32 0)
 set(CADABRA_CMAKE_VERSION 3.1)
 
 cmake_minimum_required(VERSION ${CADABRA_CMAKE_VERSION})
-set(CMAKE_CXX_STANDARD 14)
+if (${CMAKE_VERSION} VERSION_LESS "3.8.0")
+	set(CMAKE_CXX_STANDARD 14)
+	message(STATUS "Using C++14 as you are using CMake < 3.8; consider upgrading as future versions of Cadabra may use C++17 features")
+else()
+	set(CMAKE_CXX_STANDARD 17)
+endif()
 project(Cadabra)
 
 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
@@ -146,6 +151,8 @@ endif()
 # - Turn optimizations on
 # - Turn off warnings we don't need
 
+
+
 # GCC
 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
 	if (ENABLE_FRONTEND)

c++lib/CMakeLists.txt

@@ -1,5 +1,12 @@
 cmake_minimum_required(VERSION 2.8)
-set(CMAKE_CXX_STANDARD 14)
+
+if(${CMAKE_VERSION} VERSION_LESS "3.8.0")
+	set(CMAKE_CXX_STANDARD 14)
+	message(STATUS "Using C++14 as you are using CMkake < 3.8, consider upgrading as future versions of Cadabra may make use of C++17 features")
+else()
+	set(CMAKE_CXX_STANDARD 17)
+endif()
+
 project(Cadabra)
 
 #---------------------------------------------------------------------------
@@ -42,11 +49,11 @@ if(CMAKE_COMPILER_IS_GNUCXX)
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
-   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -O2")
+   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")
 endif()
 
 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -O2")
+   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")
 endif()
 
 if(MSVC)

frontend/web/CMakeLists.txt

@@ -5,7 +5,12 @@ cmake_minimum_required(VERSION 3.5)
 
 project(CadabraWeb)
 
-set(CMAKE_CXX_STANDARD 14)
+if(${CMAKE_VERSION} VERSION_LESS "3.8.0")
+	message(STATUS "Using C++14 as you are using CMake < 3.8, consider upgrading as future versions of Cadabra may use C++17 features)
+	set(CMAKE_CXX_STANDARD 14)
+else()
+	set(CMAKE_CXX_STANDARD 17)
+endif()
 
 if(NOT "${CMAKE_SYSTEM_NAME}" STREQUAL "Emscripten")
   message(FATAL_ERROR