TryParse with out var param

Question

A new feature in C# 6.0 allows to declare variable inside TryParse method. I have some code:

string s = "Hello";  if (int.TryParse(s, out var result)) {  } 

But I receive compile errors:

What I am doing wrong? P.S.: in project settings C# 6.0 and .NET framework 4.6 are set.

Answer 1

A new feature in C# 6.0 allows to declare variable inside TryParse method.

Declaration expressions was cut from C# 6.0 and wasn't shipped in the final release. You currently can't do that. There is a proposal for it on GitHub for C# 7 (also see this for future reference).

Update (07/03/2017)

With the official release of C#7, the following code compiles:

string s = "42";  if (int.TryParse(s, out var result)) {      Console.WriteLine(result); } 

Answer 2

Just found out by accident, in vs2017, you can do this for brevity:

if (!Int64.TryParse(id, out _)) {    // error or whatever... }