/// <summary>
/// <para>Return list, reversed or not, with elements not fulfilling [f] removed.
/// Avoid allocation if possible.
///
/// </para>
/// </summary>
public list <T> RevFilterWhenNeeded(Function <T, bool> f)
{
return((!NList.ForAll <T>(this, f)) ? NList.RevFilter <T>(this, f) : this);
}
/// <summary>
/// <para>Returns 'true' if all of the 'l' list's elements satisfy
/// the condition 'f'.
///
/// </para>
/// </summary> <remarks><para>Example of use:
///
/// </para> <para>NList.ForAll ([2, 4, 6, 8], fun (x) { x % 2 == 0 })
///
/// </para> <para>evaluates to 'true' as all the list's elements are even.
///
/// </para></remarks>
public bool ForAll(Function <T, bool> f)
{
return(NList.ForAll <T>(this, f));
}
