Determine C++ version at library configure time, not at client build time.

c0570165 · Martin Heistermann · 9744578e · c0570165 · c0570165
Commit c0570165 authored Aug 19, 2019 by Martin Heistermann
--- a/src/OpenVolumeMesh/Config/Version.hh.in
+++ b/src/OpenVolumeMesh/Config/Version.hh.in
@@ -5,3 +5,5 @@
 #define  OPENVOLUMEMESH_VERSION_MINOR @OpenVolumeMesh_VERSION_MINOR@
 #define  OPENVOLUMEMESH_VERSION_PATCH @OpenVolumeMesh_VERSION_PATCH@

+#define  OPENVOLUMEMESH_CXX_VERSION @OVM_CXX_VERSION@
+
--- a/src/OpenVolumeMesh/System/Compiler.hh
+++ b/src/OpenVolumeMesh/System/Compiler.hh
-#if __cplusplus >= 201402L
-    #define OVM_CXX_14 1
-#else
-    #define OVM_CXX_14 0
-#endif
+#include "../Config/Version.hh"

-#if __cplusplus >= 201703L
+#if OPENVOLUMEMESH_CXX_VERSION >= 17
    #define OVM_CXX_17 1
 #else
    #define OVM_CXX_17 0