/// <summary>
/// Returns the minimum element of the sequence according to the specified selector - or null if the source collection
/// is empty or null.
/// </summary>
/// <remarks>
/// Throw ArgumentNullException if source is null
/// </remarks>
/// <typeparam name="TSource"></typeparam>
/// <typeparam name="TResult"></typeparam>
/// <param name="source"></param>
/// <param name="selector"></param>
/// <returns></returns>
public static TResult?MinOrNullIfNull <TSource, TResult>(this IEnumerable <TSource> source, Func <TSource, TResult> selector) where TResult : struct, IComparable
{
return(LinqExtensions.NullableFunctionWrapper(source, src => src.Min(selector)));
}
/// <summary>
/// Returns the maximum element of the sequence according to the specified selector - or null if the source collection
/// is empty.
/// <para />
/// Throw ArgumentNullException if source is null
/// </summary>
/// <typeparam name="TSource"></typeparam>
/// <typeparam name="TResult"></typeparam>
/// <param name="source"></param>
/// <param name="selector"></param>
/// <returns></returns>
public static TResult?MaxOrNull <TSource, TResult>(this IEnumerable <TSource> source, Func <TSource, TResult> selector) where TResult : struct, IComparable
{
source.CheckArgumentNull(nameof(source));
return(LinqExtensions.NullableFunctionWrapper(source, src => src.Max(selector)));
}