gistfile1.txt

Welcome to Scala version 2.11.4 (OpenJDK 64-Bit Server VM, Java 1.6.0_27).
Type in expressions to have them evaluated.
Type :help for more information.

scala> case class Foo[T](name: String)
defined class Foo

scala> implicit val stringFoo = Foo[String]("String")
stringFoo: Foo[String] = Foo(String)

scala> implicit val intFoo = Foo[Int]("Int")
intFoo: Foo[Int] = Foo(Int)

scala> case class Bar[T]()(implicit foo: Foo[T]) { println(foo.name) }
defined class Bar

scala> val bar = Bar()
<console>:13: error: ambiguous implicit values:
 both value stringFoo of type => Foo[String]
 and value intFoo of type => Foo[Int]
 match expected type Foo[T]
       val bar = Bar()
                    ^

scala> val bar: Bar[Int] = Bar()
Int
bar: Bar[Int] = Bar()