gsharp gsharp - 1 month ago 22
C# Question

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?

Answer

If you're targeting .NET 4.6.1 or lower or .NET Core, you need to install the NuGet package System.ValueTuple:

Install-Package "System.ValueTuple" -IncludePrerelease