public static Func<T, int> CreateComparer<T,K>(Func<T,K> conv, Func<K,K, int> comp, K fieldVal) {
    return (T t) => { return comp(conv(t), fieldVal); };
}

public static int BinarySearch<T>(this IList<T> list, Func<T, int> comparer)
{
    var left = 0;
    var right = list.Count - 1;

    while (left <= right)
    {
        var mid = left + (right - left) / 2;
        var cmp = comparer(list[mid]);

        if (cmp == 0)
            return mid;

        if (cmp < 0)
            right = mid - 1;
        else
            left = mid + 1;
    }

    return ~left; // индекс вставки с битовым дополнением
}

        class MyComparer2<TAttr> : IComparer {
            private Func<TAttr, TAttr, int> cmp;
            public MyComparer2(Func<TAttr, TAttr, int> cmp) {
                this.cmp = cmp;
            }
            public int Compare(object x, object y) {
                return cmp((TAttr)x, (TAttr)y);
            }
        }

        class Wrapper<TAttr,TObj>: IList {

            private IList<TObj> data;
            private Func<TObj, TAttr> conv;

            public Wrapper(IList<TObj> data, Func<TObj, TAttr> conv) {
                this.data = data;
                this.conv = conv;
            }

            public object this[int index] {
                get {
                    return conv(data[index]);
                }
                set {
                    throw new NotImplementedException();
                }
            }

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

            #region notimpl

            public int Add(object value) {
                throw new NotImplementedException();
            }

            public void Clear() {
                throw new NotImplementedException();
            }

            public bool Contains(object value) {
                throw new NotImplementedException();
            }

            public int IndexOf(object value) {
                throw new NotImplementedException();
            }

            public void Insert(int index, object value) {
                throw new NotImplementedException();
            }

            public bool IsFixedSize {
                get { throw new NotImplementedException(); }
            }

            public bool IsReadOnly {
                get { throw new NotImplementedException(); }
            }

            public void Remove(object value) {
                throw new NotImplementedException();
            }

            public void RemoveAt(int index) {
                throw new NotImplementedException();
            }

            public void CopyTo(Array array, int index) {
                throw new NotImplementedException();
            }


            public bool IsSynchronized {
                get { throw new NotImplementedException(); }
            }

            public object SyncRoot {
                get { throw new NotImplementedException(); }
            }

            public IEnumerator GetEnumerator() {
                throw new NotImplementedException();
            }

            #endregion notimpl
        }

    }