[Proposal] Keyword to implement interface through member.

[aquartulli]

Syntactic sugar, but given some interface:

interface IFoo
{
    void Bar();
}

It would be great to have syntax that automatically expands a class to implement an interface through a member, such as:

class Foo : IFoo
{
    private readonly IFoo _Foo : IFoo;
}

expands into

class Foo : IFoo
{
    private readonly IFoo _Foo;

    public void Bar() => _Foo.Bar();
}

This just saves a lot of boilerplate code. Any member that returns an IFoo, be it a field, property, or method, may be a viable keyword target. Additionally there may be a keyword to signify that the compiler should generate explicit interface members.

If the author defines any class members that match an interface member then the compiler will not generate a wrapper member. If the author used a keyword to generate an explicit interface implementation, then an explicit interface member will be generated even if there is a matching class member unless the class member is also an explicit interface member.

[Joe4evr]

Duplicate of #900.

In the mean time, you can make use of the built-in codefix to write all of that code out for you.

[DaZombieKiller]

I believe this would be quite easily solved with source generators.

[aquartulli]

Duplicate of #900.

In the mean time, you can make use of the built-in codefix to write all of that code out for you.

This is not the same as #900, as it doesn't compromise type safety nor developer intent. This is just a syntactical sugar change in the same vein as null coalescence - already doable, but common enough that it's simplified. Implementing an interface through another object is also a fairly common and well established pattern.