//using Bridge;

using System;

using System.Collections.Generic;

using System.Linq;

​

namespace SomeName {

    public class A {

        public string P {get; set; }

        public A() {

            P = ""; //dotnetfiddle doesn't support property initializer

        }

        public override string ToString() 

        {

            return P;

        }

    }

    public class B {

        public static string Fail<T>(T v, Func<T,string> transform)  {

            return transform(v);

        }

​

        public static string Fail2<T>(Func<T,string> transform)  {

            return transform(default(T));

        }

​

        public static string Fine<T>(T v) {

            return v.ToString();

        }

​

        public static A Helper(A aaa) 

        {

            return aaa;

        }

    }

​

    public class SomeName {

        private static void AssertEquals(object exp, object fact) {

            if (!exp.Equals(fact)) {

                throw new Exception("AssertEquals failed");

            }

        } 

//        [Ready]

        public static void Main() {

            AssertEquals("123456", B.Fail(new A {P = "123"}, x => x.P+"456")); //this fails in 17.4.0

            AssertEquals("678", B.Fail2((A x) => x+"678")); //this fails in 17.4.0

            AssertEquals("123456", B.Fail<A>(new A {P = "123"}, x => x.P+"456")); //workaround for 17.4.0

            AssertEquals("678", B.Fail2<A>((A x) => x+"678")); //workaround for 17.4.0

​

            AssertEquals("13", B.Fine(new A {P = "13"}));

            var lst = new List<A> {new A {P = "22"} };

            var lstFail = lst.Select(z => {

                    return B.Helper(z);

                }).ToList(); //this fails in 17.4.0

​

            AssertEquals(1, lstFail.Count);

            AssertEquals("22", lstFail[0].P);

​

            var lstWorkaround = lst.Select<A,A>(z => {

                return B.Helper(z);

            }).ToList(); //workaround for 17.4.0

​

            AssertEquals(1, lstWorkaround.Count);

            AssertEquals("22", lstFail[0].P);

            Console.WriteLine("done");

    }

    }

}