diff --git a/internal/ceres/split.h b/internal/ceres/split.h
new file mode 100644
index 0000000..ec579e9
--- /dev/null
+++ b/internal/ceres/split.h
@@ -0,0 +1,21 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Author: keir@google.com (Keir Mierle)
+
+#ifndef CERES_INTERNAL_SPLIT_H_
+#define VISION_OPTIMIZATION_LEAST_SQUARES_INTERNAL_SPLIT_H_
+
+#include <string>
+#include <vector>
+#include "ceres/internal/port.h"
+
+namespace ceres {
+
+// Split a string using one or more character delimiters, presented as a
+// nul-terminated c string. Append the components to 'result'. If there are
+// consecutive delimiters, this function skips over all of them.
+void SplitStringUsing(const string& full, const char* delim,
+                      vector<string>* res);
+
+}  // namespace ceres
+
+#endif  // CERES_INTERNAL_SPLIT_H_