C# Pie!

pie.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace Confections
{
    public class Pie<T> : IReadOnlyCollection<Slice<T>>
    {
        readonly List<Slice<T>> slices;

        public Pie(IEnumerable<Slice<T>> slices)
        {
            this.slices = slices.ToList();

            if (Math.Abs(this.slices.Sum(s => s.Percent) - 100) > 0.1)
                throw new ArgumentOutOfRangeException("Slices must add up to 100%");
        }

        public IEnumerator<Slice<T>> GetEnumerator()
        {
            return slices.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public int Count
        {
            get { return slices.Count; }
        }
    }

    public class Slice<T>
    {
        public Slice(double percent, string name)
        {
            if (percent > 100.0 || percent < 1.0)
                throw new ArgumentOutOfRangeException("Size must be between 1 and 100.");

            Percent = percent;
            Name = name;
        }

        public double Percent { get; private set; }

        public string Name { get; private set; }

        public List<T> Filling { get; set; }
    }
}