Contract::connect should be able to connect to different middleware types

[prestwich]

Contract::<M>::connect has this following signature pub fn connect(&self, client: Arc<M>) -> Self

This allows the contract to connect to different instances of the same provider. Instead it should have signature:

pub fn connect<N>(&self, client: Arc<N>) -> Contract<N>
    where
        N: Middleware + Clone

This would allow contracts to change provider types when calling connect.

proposed impl:

#[must_use]
    pub fn connect(&self, client: Arc<M>) -> Contract<N>
    where
        M: Clone,
    {
        Contract::<N>::new(self.address, self.base_contract.clone(), client)
    }

[mattsse]

nice catch!
can add this in a bit

[prestwich]

another easy change might be adding connect to the output of abigen so that it doesn't erase the specialized type of the abigen contract and give you a generic Contract

[prestwich]

(that's not a big deal as there's a From impl but it'd be nice to drop the into)

// current:
let b: AbigenContract = AbigenContract.connect(new_provider).into();

// desired
let b: AbigenContract = AbigenContract.connect(new_provider);

[mattsse]

yeh the connect is acutally the Contract::connect function (because of the deref impl) since the generated type is just a wrapper type.

I guess we can just generate another connect function?