/// <summary>
/// Helper method to get the next unit to redo, or throw an <see cref="InvalidOperationException"/>.
/// </summary>
/// <typeparam name="T">The type of undo units.</typeparam>
/// <param name="buffer">The <see cref="UndoUnitBuffer{T}"/>.</param>
/// <returns>The next unit to redo.</returns>
/// <remarks>
/// This is a <c>O(1)</c> operation in time complexity.
/// </remarks>
/// <exception cref="InvalidOperationException">If there are no more units to redo.</exception>
public static T GetNextToRedo <T>(this UndoUnitBuffer <T> buffer)
{
T retVal;
if (!buffer.TryGetNextToRedo(out retVal))
{
buffer.ThrowUnderflow(false);
}
return(retVal);
}
/// <summary>
/// Helper method to check whether given <see cref="UndoUnitBuffer{T}"/> can perform an redo operation.
/// </summary>
/// <typeparam name="T">The type of undo units.</typeparam>
/// <param name="buffer">The <see cref="UndoUnitBuffer{T}"/>.</param>
/// <returns><c>true</c> if <paramref name="buffer"/> is in such state that redo operation is possible; <c>false</c> otherwise.</returns>
/// <remarks>
/// This is a <c>O(1)</c> operation in time complexity.
/// </remarks>
public static Boolean CanRedo <T>(this UndoUnitBuffer <T> buffer)
{
T dummy;
return(buffer.TryGetNextToRedo(out dummy));
}
