Conditional scalacOptions with SBT

Question

I am using a project with cross-build for Scala 2.8, 2.9 and (hopefully) 2.10, using SBT. I would like to add the -feature option when compiling with 2.10 only.

Answer 1

When cross-building, scalaVersion reflects the version your project is currently built against. So depending on scalaVersion should do the trick:

val scalaVersionRegex = "(\\d+)\\.(\\d+).*".r
...
scalacOptions <++= scalaVersion { sv =>
  sv match {
    case scalaVersionRegex(major, minor) if major.toInt > 2 || (major == "2" && minor.toInt >= 10) =>
      Seq( "-deprecation", "-unchecked", "-feature" )
    case _ => Seq( "-deprecation", "-unchecked" )
}