title: C# 6, VS2015-3, .Net 4.6, System.Numerics.Vectors has no Vector<T>
body: <p>I am upgrading an application from Visual Studio 2013 Net 4.5.1 to Visual Studio 2015 C#6 Net 4.6, and I would like to make use of the <code>System.Numerics.Vectors Vector&lt; T &gt;</code>.  I have been using Vector4 already to get SIMD which works fine in my app, I would like to get Vector&lt; T > support though and make full use of the larger AVX/AVX2 SIMD Registers.</p>
  
  <p>The development system has Net 4.5, 4.51, 4.52, 4.6, 4.61 and 4.62 Multi-Target Packs and SDKs installed.
  The project properties Target Framework is 4.6.  I also tried 4.61.
  The project references include both <code>System.Numerics</code> (4.6.81.0) and <code>System.Numerics.Vectors</code> (4.6.81.0).</p>
  
  <p>But all that I get in the <code>System.Numerics</code> namespace is the BigInteger, Complex, Matrix3x2/4x4, Plane, Quaternion, Vector2/3/4.
  I do not get Vector&lt; T >.</p>
  
  <p>At this late stage (2019) am I still supposed to install the old NuGet Preview packages to still get the Vector&lt; T >?  Is Vector&lt; T > not by now a part of the current .Net 4.6 and 4.61 public releases?
  And if I do have to use the old NuGet, is the NuGet package just the relevant information for VS and the JIT, or does that mean that I have to distribute another DLL even though <code>System.Numerics.Vectors</code> is already on the system...</p>
  
  <p>I must be stupid...</p>