Predefined type ‘System.ValueTuple´2´ is not defined or imported

I’ve installed Visual Studio 15 Preview 3 and tried to use the new tuple feature

static void Main(string[] args)
{
    var x = DoSomething();
    Console.WriteLine(x.x);
}

static (int x, int y) DoSomething()
{
    return (1, 2);
}

When I compile I get the error:

Predefined type ‘System.ValueTuple´2´ is not defined or imported

According to the blog post, this features should be “on” by default.

What did I do wrong?

10 Answers
10

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