From 92f44407c69355966d62b546fabb3b3fb4a89d7b Mon Sep 17 00:00:00 2001
From: Jack Andersen <jackoalan@gmail.com>
Date: Fri, 10 Apr 2020 18:59:16 -1000
Subject: [PATCH] Exclude CMake CXX standard from MSVC

---
 CMakeLists.txt        | 29 +++++++++++++++++++----------
 Editor/CMakeLists.txt | 23 +++++++++++++++--------
 2 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3341e53..db0c01d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,8 +2,10 @@ cmake_minimum_required(VERSION 3.10 FATAL_ERROR) # because of c++17
 
 project(amuse)
 
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
+if (NOT MSVC)
+  set(CMAKE_CXX_STANDARD 20)
+  set(CMAKE_CXX_STANDARD_REQUIRED ON)
+endif()
 
 if(NOT MSVC)
     add_compile_options(-Wno-narrowing)
@@ -98,20 +100,27 @@ endif()
 if (MSVC)
   target_compile_options(amuse PRIVATE
     # Enforce various standards compliant behavior.
-    /permissive-
+    $<$<COMPILE_LANGUAGE:CXX>:/permissive->
 
     # Enable standard volatile semantics.
-    /volatile:iso
+    $<$<COMPILE_LANGUAGE:CXX>:/volatile:iso>
 
     # Reports the proper value for the __cplusplus preprocessor macro.
-    /Zc:__cplusplus
+    $<$<COMPILE_LANGUAGE:CXX>:/Zc:__cplusplus>
 
-    # Allow constexpr variables to have explicit external linkage.
-    /Zc:externConstexpr
-
-    # Assume that new throws exceptions, allowing better code generation.
-    /Zc:throwingNew
+    # Use latest C++ standard.
+    $<$<COMPILE_LANGUAGE:CXX>:/std:c++latest>
   )
+  if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+    # Flags for MSVC (not clang-cl)
+    target_compile_options(amuse PRIVATE
+      # Allow constexpr variables to have explicit external linkage.
+      $<$<COMPILE_LANGUAGE:CXX>:/Zc:externConstexpr>
+
+      # Assume that new throws exceptions, allowing better code generation.
+      $<$<COMPILE_LANGUAGE:CXX>:/Zc:throwingNew>
+    )
+  endif()
 else()
   target_compile_options(amuse PRIVATE -Wno-unknown-pragmas)
 endif()
diff --git a/Editor/CMakeLists.txt b/Editor/CMakeLists.txt
index 9d9b344..e13a8f1 100644
--- a/Editor/CMakeLists.txt
+++ b/Editor/CMakeLists.txt
@@ -84,20 +84,27 @@ target_compile_definitions(amuse-gui PRIVATE
 if (MSVC)
   target_compile_options(amuse-gui PRIVATE
     # Enforce various standards compliant behavior.
-    /permissive-
+    $<$<COMPILE_LANGUAGE:CXX>:/permissive->
 
     # Enable standard volatile semantics.
-    /volatile:iso
+    $<$<COMPILE_LANGUAGE:CXX>:/volatile:iso>
 
     # Reports the proper value for the __cplusplus preprocessor macro.
-    /Zc:__cplusplus
+    $<$<COMPILE_LANGUAGE:CXX>:/Zc:__cplusplus>
 
-    # Allow constexpr variables to have explicit external linkage.
-    /Zc:externConstexpr
-
-    # Assume that new throws exceptions, allowing better code generation.
-    /Zc:throwingNew
+    # Use latest C++ standard.
+    $<$<COMPILE_LANGUAGE:CXX>:/std:c++latest>
   )
+  if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+    # Flags for MSVC (not clang-cl)
+    target_compile_options(amuse-gui PRIVATE
+      # Allow constexpr variables to have explicit external linkage.
+      $<$<COMPILE_LANGUAGE:CXX>:/Zc:externConstexpr>
+
+      # Assume that new throws exceptions, allowing better code generation.
+      $<$<COMPILE_LANGUAGE:CXX>:/Zc:throwingNew>
+    )
+  endif()
 endif()
 
 if(WIN32)