Adding necessary cstdlib include for Clang.

stgates · stgates · commit 57ca695d233c · 2015-03-02T20:49:43.000-08:00
diff --git a/Release/include/cpprest/details/SafeInt3.hpp b/Release/include/cpprest/details/SafeInt3.hpp
@@ -83,6 +83,7 @@ Please read the leading comments before using the class.
 
 // Need this for ptrdiff_t on some compilers
 #include <cstddef>
+#include <cstdlib>
 
 #if SAFEINT_COMPILER == VISUAL_STUDIO_COMPILER && defined _M_AMD64
     #include <intrin.h>
