Override Sparsam::Struct#hash method

[marionzualo]

This ensures that different Set objects with Thrift objects having the same value are considered equal.

I added a spec but I wasn't able to run it in my local environment.

I get the following error

`require': cannot load such file -- sparsam_native (LoadError)

@pariser

[pariser]

It looks like struct_fields should be deterministic based on this class_eval method signature, so that's good!

While we're at it, WDYT about adding other equality tests like us1 == us1, [us1] == [us2], { us1 => true } == { us2 => true }?

[pariser]

Looks like sparsam is not updated to use expect rspec syntax

Suggested change

	expect(Set[us1]).to eq(Set[us2])
	Set[us1].should == Set[us2]

would hopefully fix the assertion

[pariser]

Don't know too much about the way sparsam's tests are structured, but it seems strange to nest this within describe Sparsam::Serializer block

[marionzualo]

good call. I missed this.

[marionzualo]

@pariser Thanks for the feedback! I implemented it and the tests are passing now. PTAL

[andyfangdz]

To run tests, run bundle exec rake build_ext

[crazysona]

Hi @marionzualo , are you still working on this PR? I also encountered the same problem, two sets are not equal due to the hash are not overridden as well as eql?

[crazysona]

I think you need to use send(name_to_accessors(data[:name]).reader).hash