Define a single C# method which accepts any object that can be used with square brackets

Question

I'm implementing a method that, given some data retrieved via DataRowView or DbDataReader, hydrates a DTO.

So, both of the data sources implement the possibility to retrieve a particular field value through

public object this[string name] { get; }

But this behavior is not constrainted by a common interface between the two classes so I cannot use it, and have to write the hydration code twice without changing a single bit. Which is bad.

public MyDTO Hydrate(DataRowView data)
{
    MyDTO f_return = new MyDTO();
    f_return.Foo = (string)data["foo"];
    f_return.Bar = (uint)data["bar"];
    f_return.Baz = (DateTime)data["baz"];
    return f_return;
}

public MyDTO Hydrate(DbDataReader data)
{
    MyDTO f_return = new MyDTO();
    f_return.Foo = (string)data["foo"];
    f_return.Bar = (uint)data["bar"];
    f_return.Baz = (DateTime)data["baz"];
    return f_return;
}

Am I missing some C# syntax that would allow me to define a single method which constraints the input to any object that can be accessed via square brackets?

Something like this

public MyDTO Hydrate(object[string] data)

Thanks in advance!

Answer 1

Am I missing some C# syntax that would allow me to define a single method which constraints the input to any object that can be accessed via square brackets?

No; there's no C# syntax for expressing "something that is indexable", other than creating an interface with that indexer, ie

interface ISomeInterface {
    object this[string name] {get;}
}

and limiting yourself to instances of ISomeInterface , or some generic <T> with the where T : ISomeInterface constraint.