/// <summary> <!-- {{{1 --> Constructor
/// </summary>
/// <param name="initial"></param>
public Value(SudokuValue initial)
{
if (!initial.IsNA() && initial.IsInvalid())
{
var msg = string.Format("Invalid value: {0}", initial.ToStr());
throw new ArgumentOutOfRangeException(msg);
}
this.v = initial;
}
/// <summary> <!-- {{{1 --> Return true if the value is valid or NA.
/// </summary>
/// <param name="self"></param>
/// <returns></returns>
public static bool IsValidOrNA(this SudokuValue self)
{
return(self.IsValid() || self.IsNA());
}