From 55f4987f42adea646c476e1cc6e772f47284714b Mon Sep 17 00:00:00 2001
From: Michael Raskin <7c6f434c@mail.ru>
Date: Sun, 27 Apr 2008 23:17:24 +0000
Subject: [PATCH] Added optionalString (similar to optional)

svn path=/nixpkgs/trunk/; revision=11733
---
 pkgs/lib/default.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkgs/lib/default.nix b/pkgs/lib/default.nix
index a99f09c80dfb..8093c67a6923 100644
--- a/pkgs/lib/default.nix
+++ b/pkgs/lib/default.nix
@@ -201,6 +201,7 @@ rec {
   # Return a list or an empty list, dependening on a boolean value.
   optionals = cond: elems: if cond then elems else [];
 
+  optionalString = cond: string: if cond then string else "";
 
   # Return a list of integers from `first' up to and including `last'.
   range = first: last: