Error CS0305 Using the generic type 'Memory' requires 1 type arguments

Question

I have the below snippet of code to test/use dotnet 2.1 in vs 2017 in order to try out and run C# 7.2s Span functionality. Where can I find the SDK that allows me to run this within Visual Studio. I can only find frameworks up to 2.0.

using System;
using System.Memory;

namespace sim
{
class Program
{
    static void Main(string[] args)
    {

       var arr = new byte[10];
        Span<byte> bytes = arr; // Implicit cast from T[] to Span<T>

        Span<byte> slicedBytes = bytes.Slice(start: 5, length: 2);

    }      
}
}

Otherwise I'm left unable to run and use Error CS0305 Using the generic type 'Memory' requires 1 type arguments sim

.NET Core 2.1 is still in preview: github.com/dotnet/core/blob/master/roadmap.md — UnholySheep
But there's the VS2017 preview which presumably works with the 2.1 preview: visualstudio.com/vs/preview — Jon Skeet

Kahbazi Kahbazi · Accepted Answer · 2018-04-19T09:12:31

You do not need to install any SDK for using Span<T>

You need to install System.Memory nuget package which is prerelase version.

you can use this command

Install-Package System.Memory -Version 4.5.0-preview2-26406-04

You also need to set your language version to 7.2 in your project properties and also you need Visual Studio 15.5 or more

Error CS0305 Using the generic type 'Memory' requires 1 type arguments

2 Answers