From d1cbc06c67a89528f4a8c03a0e37c6582635497a Mon Sep 17 00:00:00 2001
From: graham <g.macpherson@opencfd.co.uk>
Date: Wed, 10 Nov 2010 10:50:59 +0000
Subject: [PATCH] ENH:  UList shuffle function to randomly reorder a list.

---
 src/OpenFOAM/containers/Lists/UList/UList.C | 7 +++++++
 src/OpenFOAM/containers/Lists/UList/UList.H | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/src/OpenFOAM/containers/Lists/UList/UList.C b/src/OpenFOAM/containers/Lists/UList/UList.C
index 7f3e63d421..25334db0c5 100644
--- a/src/OpenFOAM/containers/Lists/UList/UList.C
+++ b/src/OpenFOAM/containers/Lists/UList/UList.C
@@ -145,6 +145,13 @@ void Foam::stableSort(UList<T>& a, const Cmp& cmp)
 }
 
 
+template<class T>
+void Foam::shuffle(UList<T>& a)
+{
+    std::random_shuffle(a.begin(), a.end());
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 template<class T>
diff --git a/src/OpenFOAM/containers/Lists/UList/UList.H b/src/OpenFOAM/containers/Lists/UList/UList.H
index d0cb05fc17..4a4dd598d9 100644
--- a/src/OpenFOAM/containers/Lists/UList/UList.H
+++ b/src/OpenFOAM/containers/Lists/UList/UList.H
@@ -344,6 +344,9 @@ void stableSort(UList<T>&);
 template<class T, class Cmp>
 void stableSort(UList<T>&, const Cmp&);
 
+template<class T>
+void shuffle(UList<T>&);
+
 // Reverse the first n elements of the list
 template<class T>
 inline void reverse(UList<T>&, const label n);