Restart a foreach loop in C#?

Question

How can I restart a foreach loop in C#??

For example:

Action a;
foreach(Constrain c in Constrains)
{
   if(!c.Allows(a))
   {
      a.Change         


        

Answer 1

for (var en = Constrains.GetEnumerator(); en.MoveNext(); )
{
    var c = en.Current;
    if (!c.Allows(a))
    {
        a.Change();
        en = Constrains.GetEnumerator();
    }
}