1 files changed, 13 insertions, 0 deletions
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 44e13a49d7..08febb5585 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -2463,6 +2463,19 @@ static Real *BigDecimal_new(int argc, VALUE *argv);
  *
  * The actual number of significant digits used in computation is usually
  * larger than the specified number.
+ *
+ * ==== Exceptions
+ *
+ * TypeError:: If the +initial+ type is neither Fixnum, Bignum, Float,
+ *             Rational, nor BigDecimal, this exception is raised.
+ *
+ * TypeError:: If the +digits+ is not a Fixnum, this exception is raised.
+ *
+ * ArgumentError:: If +initial+ is a Float, and the +digits+ is larger than
+ *                 Float::DIG + 1, this exception is raised.
+ *
+ * ArgumentError:: If the +initial+ is a Float or Rational, and the +digits+
+ *                 value is omitted, this exception is raised.
  */
 static VALUE
 BigDecimal_initialize(int argc, VALUE *argv, VALUE self)