Polish torch::Dict (#23344)
Summary:
torch::List recently received some polishing that now also is done for Dict. This should be done before the PyTorch 1.2 release because of backwards compatibility.
- Dict is just a reference type, so "const Dict" should have the same capabilities as "Dict", constness is not guaranteed in any way.
- DictIterator gets comparison operators <, <=, >, >=
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23344
ghstack-source-id: 87170304
Differential Revision: D16468800
fbshipit-source-id: 2978c3b9cdcfb2cfb3f26516b15bd455d9a48ba9
