Compiler Error CS8158

Cannot return by reference a member because it was initialized to a value that cannot be returned by reference

Example

The following sample generates CS8158:

// CS8158.cs (11,14)

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

    ref char Test1(char arg1, S1 arg2)
    {
        ref S1 r = ref arg2;
        return ref r.x;
    }
}

To correct this error

To return members initialized to a value that cannot be returned by reference, refactoring to return by value corrects this error:

    char Test1(char arg1, S1 arg2)
    {
        ref S1 r = ref arg2;
        return r.x;
    }