Compiler Error CS8163

Fields of static readonly field cannot be returned by writable reference

Example

The following sample generates CS8163:

// CS8163.cs (12,14)
public class Test
{
    public struct S1
    {
        public char x;
    }

    public static readonly S1 s2;

    char Test2()
    {
        return s2.x;
    }
}

To correct this error

To return the value of a static readonly field, refactoring to return by value corrects this error:

public class Test
{
    public struct S1
    {
        public char x;
    }

    public static readonly S1 s2;

    char Test2()
    {
        return s2.x;
    }
}