Created
March 25, 2014 09:21
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test a type has some type class instance in scope
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| trait TypeClass1[T] | |
| trait TypeClass2[V] | |
| implicit object StringIsTypeClass1 extends TypeClass1[String] | |
| def test[X, M[_]](implicit ev: M[X] = null.asInstanceOf[M[X]]): Boolean = { | |
| ev != null | |
| } | |
| assert(test[String, TypeClass1] == true) | |
| assert(test[String, TypeClass2] == false) |
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