Don - I'm not really sure if I'm thinking along the same lines here - I'm thinking for just syntactic sugar for either the duck-typing support that already exists in F#. I don't even know how this works internally (is the structural constraint erased at runtime? what's the signature of the method at runtime?).
This could even be something that was erased away at compile-time and resorted to something less than that at runtime (in a similar way to units of measure?). I don't know :-)
You can get this to work with backtick declarations which let you put lots of stuff e.g. spaces in the declaration e.g.
let ``odd?`` a = a % 2 <> 0
Intellisense in e.g. Visual Studio doesn't work for them though, unfortunately.
What makes you think they were suggested by the core team? You can see the names of people that have raised each of the completed features.
31 votesplanned · Adminfsharporg-lang (F# Software Foundation Language Group, F# Software Foundation) responded
Thanks for the suggestion. Approved in principle.
We will open an RFC for this in due course https://github.com/fsharp/FSharpLangDesign/tree/master/RFCs