How to disable all implicit conversion of primitive types?

Question

Scala seems to behave like Java when it comes to the magic conversion of primitives:

val a: Int = 1
val b: Double = 2.3
println(a + b) // 3.3 
println(Math.max(a, b)) // 2.3

More often than not, this has been a source of bugs in my code. Is there a way to disable these implicit conversions so that my example give a compilation warnning/error? I would really rather have to write

print(a.toDouble + b)
println(Math.max(a.toDouble, b))

every single time I need such conversions.

Answer 1

Use WartRemover. A wart like that isn't built-in, but could be written (see "Writing Wart Rules" in README). Though now that I think, it's probably more work than I thought initially.

scalac also has -Ywarn-numeric-widen option (together with -Xfatal-warnings to turn the warnings to errors), but I don't know if there are any cases not covered by it.