add compare

AnjuDel · AnjuDel · commit 9f9558147c6a · 2021-02-09T10:29:54.000-08:00
diff --git a/stl/inc/xstring b/stl/inc/xstring
@@ -17,6 +17,10 @@
 #include <xpolymorphic_allocator.h>
 #endif // _HAS_CXX17
 
+#if _HAS_CXX20
+#include <compare>
+#endif // _HAS_CXX20
+
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
 #pragma warning(disable : _STL_DISABLED_WARNINGS)
