Why does this work with statics but not with instance members?

[voroninp]

While this works

    private static readonly int x = 1;
    private static readonly int y = x;

Version without static modifier does not compile:

    private readonly int x = 1;
    private readonly int y = x;

And this works as well:

    private static readonly int y = x;
    private static readonly int x = 1;

Why is compiler's behavior different? I mean, what's the reasoning behind the decision to make it like that?

[HaloFour]

Without the static modifier those members are instance members and have different rules as to when they can be accessed during the instances lifetime. Field initializers take place prior to the base constructor being called, and at this time it's not permitted to access members of the class except to initialize fields.

[voroninp]

and have different rules as to when they can be accessed during the instance's lifetime

That's what I am asking about. What's the motivation for different rules.

[HaloFour]

Because otherwise it would be possible to access members of an instance that has not yet been fully constructed which can lead to unexpected behavior. Static members don't belong to any instances, thus they have no concerns about instance lifecycles.

[TahirAhmadov]

#6128

[voroninp]

Yep, that would be the next step ;-)