public T Peek()
{
if (IsEmpty)
{
throw new InvalidOperationException("Queue is empty.");
}
return(frontStack.Peek());
}
public T Peek()
{
if (this.IsEmpty)
{
throw new InvalidOperationException(SR.InvalidEmptyOperation);
}
return(_forwards.Peek());
}
/// <summary>
/// Reverses the order of a stack.
/// </summary>
/// <returns>The reversed stack.</returns>
internal ImmutableStack <T> Reverse()
{
var r = this.Clear();
for (ImmutableStack <T> f = this; !f.IsEmpty; f = f.Pop())
{
r = r.Push(f.Peek());
}
Debug.Assert(r != null);
Debug.Assert(r.IsEmpty == IsEmpty);
return(r);
}
internal ImmutableStack <T> Reverse()
{
Contract.Ensures(Contract.Result <ImmutableStack <T> >() != null);
Contract.Ensures(Contract.Result <ImmutableStack <T> >().IsEmpty == this.IsEmpty);
var r = this.Clear();
for (ImmutableStack <T> f = this; !f.IsEmpty; f = f.Pop())
{
r = r.Push(f.Peek());
}
return(r);
}