object Test {
class Rep[T](x : T)
class SomeOps[T](x : Rep[T]) { def foo = 1 }
implicit def mkOps[X, T](x : X)(implicit conv: X => Rep[T]) : SomeOps[T] = new SomeOps(conv(x))
val a: Rep[Int] = error("")
a.foo // infers mkOps(a).foo but rejects it because the types don't work out
// mkOps(a) will have type SomeOps[T] where T hasn't been instantiated because
// the implicit search for mkOps's implicit argument hasn't been performed yet
}
relevant code from Implicits.scala
/** The type parameters to instantiate */
val undetParams = if (isView) List() else context.outer.undetparams // TODO: why the empty list for a view? why is this a val?
if (itree2.tpe.isError) SearchFailure
else if (hasMatchingSymbol(itree1)) {
val tvars = undetParams map freshVar
println("matchesPt??: "+(undetParams, context.undetparams, context.outer.undetparams)) // note that they are different!
if (matchesPt(itree2.tpe /* itree2.tpe may contain typeparams from context.undetparams that will get instantiated later (during 2nd-order implicit search)*/,
pt.instantiateTypeParams(undetParams, tvars), undetParams)) {
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