postgres.git / summary / log / commit / refs

commit    ee56e14bbb6f3593e79c1d7e22b02bbc6df4b500
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Sun Dec 21 20:30:39 2014 +0000
First released in: 9.5.0, 9.0.19, 9.1.15, 9.2.10, 9.3.6, 9.4.1

    Docs: clarify treatment of variadic functions with zero variadic arguments.
    
    Explain that you have to use "VARIADIC ARRAY[]" to pass an empty array
    to a variadic parameter position.  This was already implicit in the text
    but it seems better to spell it out.
    
    Per a suggestion from David Johnston, though I didn't use his proposed
    wording.  Back-patch to all supported branches.


 doc/src/sgml/xfunc.sgml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
index e2b10703ee9..66e752c3928 100644
--- a/doc/src/sgml/xfunc.sgml
+++ b/doc/src/sgml/xfunc.sgml
@@ -739,6 +739,20 @@ SELECT mleast(VARIADIC ARRAY[10, -1, 5, 4.4]);
      actual argument of a function call.
     </para>
 
+    <para>
+     Specifying <literal>VARIADIC</> in the call is also the only way to
+     pass an empty array to a variadic function, for example:
+
+<screen>
+SELECT mleast(VARIADIC ARRAY[]::numeric[]);
+</screen>
+
+     Simply writing <literal>SELECT mleast()</> does not work because a
+     variadic parameter must match at least one actual argument.
+     (You could define a second function also named <literal>mleast</>,
+     with no parameters, if you wanted to allow such calls.)
+    </para>
+
     <para>
      The array element parameters generated from a variadic parameter are
      treated as not having any names of their own.  This means it is not


[parent: b71e37c88354]