Adding missing <string> include to pplxcancellation_token.h

stgates · stgates · commit b2511c7a942a · 2014-10-01T18:02:10.000-07:00
diff --git a/Release/include/pplx/pplxcancellation_token.h b/Release/include/pplx/pplxcancellation_token.h
@@ -36,6 +36,7 @@
 #error This file must not be included for Visual Studio 12 or later
 #endif
 
+#include <string>
 #include <pplx/pplxinterface.h>
 
 #pragma pack(push,_CRT_PACKING)
