Question

I was trying to create a generic method to read column values from a datarow using the datarowextension methods:

public static Nullable<T> SafeRead<T>(DataRow row, string fieldName) where T : struct
    {
        if (row.HasColumn(fieldName))
        {
            return row.Field<Nullable<T>>(fieldName) ?? default(Nullable<T>);
        }
        else
            return default(Nullable<T>);
    }

    public static T SafeRead<T>(DataRow row, string fieldName) where T : class
    {
        if (row.HasColumn(fieldName))
        {
            return row.Field<T>(fieldName) ?? default(T);
        }
        else
            return default(T);
    }

When I call this function from my code the compiler complains that there is an ambiguous reference between the two calls which is obvious when I look at the method signatures. However, I am not sure how to handle this without using separate methods.

Answer 1

The return value is not part of the identifying method signature. So your methods look like this to the compiler:

SafeRead<T>(DataRow row, string fieldName)

and

SafeRead<T>(DataRow row, string fieldName)

-> There is no difference.

you should rename one of the methods.