1 files changed, 22 insertions, 0 deletions
diff --git a/util/exception.hh b/util/exception.hh
index 6d6a37cb1..83f99cd6f 100644
--- a/util/exception.hh
+++ b/util/exception.hh
@@ -2,9 +2,12 @@
 #define UTIL_EXCEPTION__
 
 #include <exception>
+#include <limits>
 #include <sstream>
 #include <string>
 
+#include <inttypes.h>
+
 namespace util {
 
 template <class Except, class Data> typename Except::template ExceptionTag<Except&>::Identity operator<<(Except &e, const Data &data);
@@ -111,6 +114,25 @@ class EndOfFileException : public Exception {
     ~EndOfFileException() throw();
 };
 
+class OverflowException : public Exception {
+  public:
+    OverflowException() throw();
+    ~OverflowException() throw();
+};
+
+template <unsigned len> inline std::size_t CheckOverflowInternal(uint64_t value) {
+  UTIL_THROW_IF(value > static_cast<uint64_t>(std::numeric_limits<std::size_t>::max()), OverflowException, "Integer overflow detected.  This model is too big for 32-bit code.");
+  return value;
+}
+
+template <> inline std::size_t CheckOverflowInternal<8>(uint64_t value) {
+  return value;
+}
+
+inline std::size_t CheckOverflow(uint64_t value) {
+  return CheckOverflowInternal<sizeof(std::size_t)>(value);
+}
+
 } // namespace util
 
 #endif // UTIL_EXCEPTION__