Usage docs inaccurate

[mslinn]

The Usage section of the README for this project says:

In your code, adding this import:

import scala.collection.parallel.CollectionConverters._

will enable use of the .par method as in earlier Scala versions.

However using that import in Scala 2.12.7 results in:

object CollectionConverters is not a member of package scala.collection.parallel

The equivalent import for Scala 2.12.7 is instead:

import scala.collection.parallel._

It would be desirable for the old import to continue to work, otherwise older code will break because there is no way to conditionally import based on compiler version.

[SethTisue]

duplicate of #22?

[mslinn]

I would say this is not a duplicate because this issue reports an error in documentation that has not previously been mentioned AFAIK.

[SethTisue]

sorry, but I fail to see how this isn't exactly the same as #22. let's consolidate there: if you think something is missing from #22, please add it as a comment there.

[SethTisue]

it's also precisely the same, as far as I can tell, as what's already documented in the README at https://github.com/scala/scala-parallel-collections#cross-building-source-compatibility

Cross-building: source compatibility

Using .par is problematic in a cross-built project, since in Scala 2.13 the CollectionConverters._ import shown above is necessary, but in earlier Scala versions, that import will not compile.

You may able to avoid the problem by directly constructing your parallel collections rather than going through .par. For other possible workarounds, see #22, which is still under discussion.