What does "+" mean in reflected FullName and '*' after Member c#

Question

I'm currently dealing with reflection in c#. After:

Assembly.LoadFile(@"C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.7\System.Numerics.Vectors.dll").GetTypes()

And i found this: [System.Numerics.Matrix4x4], [System.Numerics.Matrix4x4+CanonicalBasis], [System.Numerics.Matrix4x4+VectorBasis] (There are reflected types from "System.Numerics.Vectors.dll") I know that Matrix4x4 is structture, however I can't find any info about CanonicalBasis and VectorBasis, and what "+" means in this context. I was doing further research and another strange thing is that:

Assembly.LoadFile(@"C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.7\System.Numerics.Vectors.dll").GetType("System.Numerics.Matrix4x4+VectorBasis").FullName
"System.Numerics.Matrix4x4+VectorBasis"

But:

Assembly.LoadFile(@"C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.7\System.Numerics.Vectors.dll").GetType("System.Numerics.Matrix4x4+VectorBasis").Name
"VectorBasis"

Moreover, when I looked through members of Matrix4x4+VectorBasis there is member like this:

[System.Numerics.Vector3* Element0] 

And is it raw pointer like in c++? Or what is it?

P.S. I was doing it in c# interactive, but i don't think it had any influence on results.

Answer 1

The + between class names means that the part after the + is a nested type of the type which name is before the +. For example Dictionary<string, string>+KeyCollection. KeyCollection is an inner class of Dictionary<TKey, TValue>.

The * denotes a pointer indeed, since the field mentioned is in unsafe mode:

public unsafe Vector3* Element0;

Answer 2

In the string System.Numerics.Matrix4x4+VectorBasis, + means that VectorBasis is a nested type of Matrix4x4. In this particular case VectorBasis is a nested struct inside of a class. Note that + is the same symbol not matter what kind of nested type you're dealing with:

class A
{
    public class B {}
}

struct A
{
    public struct B {}
}

class A
{
    public enum B {}  
}

All nested types in these examples have the same FullName, A+B.

In your case, VectorBasis and CanonicalBasis are private members, that's why you can't see them through Type.GetNestedTypes() which only shows public members.

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The * after System.Numerics.Vector3* means that it is a pointer type. The string comes from the Type instance of the FieldInfo.FieldType property.

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You can look up this and other possible string representations of the Type class on the corresponding page of the MSDN documentation.