c# overload generic functions with different parameter constraints

I have the following functions:

public static V AddIfNotPresent<K, V>( this Dictionary<K, V> store, K key ) where V : new()

public static V AddIfNotPresent<K, V>( this Dictionary<K, V> store, K key )

First off... 开发者_如何学Gois it possible to overload the functions in this way?

If overloading is not possible could I be more specific with my functions and implements say:

public static string Foo<K, string>( this Dictionary<K, string> store, K key )

As a little History I have a Dictionary with string values and I'd live a consistent 'Foo' extension of the Dictionary to allow me to add new() objects or an empty string (as appropriate).

---

No, you can't overload by type parameter constraints. But yes, you can overload by the number of type parameters:

public static string Foo<TKey>(this Dictionary<TKey, string> store, TKey key)

(Note that string isn't in the generic type parameters list for Foo; it's not a type parameter itself, it's just used as a type argument for Dictionary.)