Multiple (non-implicit) parameters to a symbolic/infix should be avoided

[octonato]

In #10199 we added symbolic methods to TypeMap, but as signaled by @NthPortal we should avoid this.

Triggered by:

I'm a bit late to the party here, but multiple (non-implicit) parameters to a symbolic/infix method are highly discouraged, and planned to be deprecated. See scala/scala-dev#496 and scala/scala3#4311 (comment).

Originally posted by @NthPortal in #10199

[octonato]

From my part we can remove all the new symbolic operators.

[mkurz]

... we added symbolic methods ... but ... we should avoid this

Just to make things clear, not symbolic methods should be avoided, but multi-params for this methods.

[octonato]

Yes, but we will have an imbalance in the API if we remove only a those with multi-params.

[BillyAutrey]

So for this task, I'm planning to deprecate first (to prevent sudden usage breaks). Do we want to remove all of the postfix symbol operators and refer back to updated?

Also, should I add multiple signatures for updated to match the convenience signatures here? E.g.:

def updated(entries: TypedEntry[_]*): TypedMap

[BillyAutrey]

In #11672, I opted to do the following:

• Add multiple signatures for updated, to reflect all the current usages of +
• Also, add the same signatures for removed, to have parity for - functionality.
• Mark + and - methods as deprecated.