C# Error
CS8152 – ‘{0}’ does not implement interface member ‘{1}’. ‘{2}’ cannot implement ‘{1}’ because it does not have matching return by reference.
Reason for the Error & Solution
Type does not implement interface member. cannot implement because it does not have matching return by reference.
Example
The following sample generates CS8152:
To implement an interface with a method that returns by reference, the implementation of the method must also return by reference and not by value.
// CS8152.cs (6,21)
public interface ITest
{
ref readonly int M();
}
public class Test : ITest
{
public int M() => 0;
}
To correct this error
Ensure interface methods that return by reference do not return by value. For example:
public class Test : ITest
{
int m;
public ref readonly int M() => ref m;
}
