stackalloc valuetuples

01. Program.cs

using System;

namespace Unsafe
{
    class Program
    {
        static unsafe void Main(string[] args)
        {
            var v = stackalloc (int, int)[]
            {
                (1, 1),
                (2, 2),
                (3, 3),
                (4, 4)
            };

            for (var i = 0; i < 4; i++)
            {
                Console.WriteLine(v[i]);
            }
        }
    }
}

02. Project.csproj

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>netcoreapp2.2</TargetFramework>
        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
        <LangVersion>preview</LangVersion>
    </PropertyGroup>

</Project>