C# Proposal: ability to refer to closed generic type

[molinch]

Imagine if you have the following generic struct definition:

public struct Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>
        where TPart1 : struct, IPart<T1>
        where TPart2 : struct, IPart<T2>
        where TPart3 : struct, IPart<T3>
        where TPart4 : struct, IPart<T4>
    {

        // ... some code here

        private static readonly Func<
            Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>,
            Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>>[] Modifiers = GetModifiers().ToArray();

        private static IEnumerable<Func<Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>, Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>>> GetModifiers()
        {
            return Modifier.GetModifiers<Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>>(
                // ... some code here
            );
        }

If we could refer to the current closed type definition, code would be much more readable, for example by using Self:

public struct Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>
        where TPart1 : struct, IPart<T1>
        where TPart2 : struct, IPart<T2>
        where TPart3 : struct, IPart<T3>
        where TPart4 : struct, IPart<T4>
    {

        // ... some code here

        private static readonly Func<Self, Self>[] Modifiers = GetModifiers().ToArray();

        private static IEnumerable<Func<Self,Self>> GetModifiers()
        {
            return Modifier.GetModifiers<Self>(
                // ... some code here
            );
        }

If you believe it could be useful I would be happy to make a roslyn PR. I would need some guidance though.

[jnm2]

There are proposals for a this type which might be supersets of this proposal.

[HaloFour]

Could also be a good use case for scoped aliases that can refer to the generic type arguements, e.g.:

public struct Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>
        where TPart1 : struct, IPart<T1>
        where TPart2 : struct, IPart<T2>
        where TPart3 : struct, IPart<T3>
        where TPart4 : struct, IPart<T4>
    {
        using Self = Identifier<TPart1, TPart2, TPart3, TPart4, T1, T2, T3, T4>;

        // ... some code here

        private static readonly Func<Self, Self>[] Modifiers = GetModifiers().ToArray();

        private static IEnumerable<Func<Self,Self>> GetModifiers()
        {
            return Modifier.GetModifiers<Self>(
                // ... some code here
            );
        }

[molinch]

@HaloFour That would be even better, I really miss this ability