EnumerableEx, Enumerable Extension.

EnumerableEx.cs

using System.Collections.Generic;

namespace Cores.Tools
{
    public static class EnumerableEx
    {
        public static bool Unanimous<T>(this IEnumerable<T> enumerable)
        {
            using var enumerator = enumerable.GetEnumerator();
            if (enumerator.MoveNext())
            {
                var current = enumerator.Current;
                while (enumerator.MoveNext())
                {
                    if (!Equals(current, enumerator.Current)) return false;
                }
            }

            return true;
        }
    }
}