Explicitly call static constructor in base static constructor

问题

This one's a little weird/complex and more just curiosity than anything.

I was looking for a way to make sure static calls from a base class could safely use static information set up in a derived class. I then noticed that C# allows me to call the derived class static constructor in the base class static constructor.

My question: Is is safe to call the derived class static constructor in the base class static constructor

Here is some sample code:

public abstract class Enumeration<TEnum, TValue>
    where TEnum : Enumeration<TEnum, TValue> // << Note the CRTP-ish thing
    where TValue: class
{
    private static readonly Dictionary<string, Enumeration<TEnum, TValue>> Mapping = new Dictionary<string, Enumeration<TEnum, TValue>>();
    public TValue Value { get; }
    public string Name { get; }

    // Base class calling derived static constructor. This sets up "Mapping" with derived class enumerations
    static Enumeration()
    {
        System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(typeof(TEnum).TypeHandle);
    }

    // Static member "Mapping" filled using this constructor when derived class statics are initialized
    protected Enumeration(TValue enumValue, string name)
    {
        Value = enumValue;
        Name = name;
        Mapping.Add(name, this);
    }

    // Uses "Mapping", so "Mappings" needs to be filled before this is called.
    protected static IEnumerable<TEnum> All => Mapping.Values.AsEnumerable().Cast<TEnum>();

    public override string ToString() { return Name; }
}

public sealed class DerivedEnum : Enumeration<DerivedEnum, String>
{
    // This static member will input itself into the static "Mapping" in the base class
    public static readonly DerivedEnum A = new DerivedEnum("A", "A");

    private DerivedEnum(string val, string name) : base(val, name) {}
}

I have done several basic tests and it doesn't seem to break. Is there a way this could break?

Here is a fiddle if you need to... fiddle: https://dotnetfiddle.net/mREPyL

Also, my code is inspired by this answer. I wanted to see if I could get the derived classes more succinct.

来源：https://stackoverflow.com/questions/55290034/explicitly-call-static-constructor-in-base-static-constructor