1 files changed, 15 insertions, 0 deletions
diff --git a/src/H5public.h b/src/H5public.h
index 2e07a24..04550c0 100644
--- a/src/H5public.h
+++ b/src/H5public.h
@@ -45,6 +45,21 @@
  */
 typedef int herr_t;
 
+
+/*
+ * Status return values for the `herr_t' type.
+ * Since some unix/c routines use 0 and -1 (or more precisely, non-negative
+ * vs. negative) as their return code, and some assumption had been made in
+ * the code about that, it is important to keep these constants the same
+ * values.  When checking the success or failure of an integer-valued
+ * function, remember to compare against zero and not one of these two
+ * values.
+ */
+#define SUCCEED         0
+#define FAIL            (-1)
+#define UFAIL           (unsigned)(-1)
+
+
 /*
  * Boolean type.  Successful return values are zero (false) or positive
  * (true). The typical true value is 1 but don't bet on it.  Boolean