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POIs there a way to implicitly convert an implicit parameter in Scala?
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  1. POIs there a way to implicitly convert an implicit parameter in Scala?
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    copied!<p>Is there a way to make this work (Scala 2.8.1):</p> <pre><code>class A class B def f(implicit b: B) {} implicit val a = new A implicit def aToB(a: A) = new B f(a) // works ok f // error: could not find implicit value for parameter b: B </code></pre> <p>Actually my problem is with Lift's (2.2) dependency injection, i'm trying to convert Vendor[T] to T and implicitly require it in a class constructor without adding imports after each val:</p> <pre><code>object DependencyFactory extends Factory { implicit def vendorToVal[T](vendor: Vendor[T]): T = vendor.vend implicit val db = new FactoryMaker[DbAccess](Model) {} //uncommenting the following line makes it work, but can we avoid it? //import db._ implicit val userStore = new FactoryMaker[UserStore](new UserStore) {} } </code></pre> <p>Where <code>UserStore</code> is:</p> <pre><code>class UserStore(implicit db: DbAccess) </code></pre> <p>Am i doing something wrong?</p> <p><strong>UPDATE</strong></p> <p>Thanks to <em>Easy Angel</em> for answering the first part. But it doesn't solve my Lift DI problem because it turns out that there is an opposite conversion in scope (from T to Vendor[T]) and having those both leads to 'error: diverging implicit expansion'.</p> <p>Can it be solved?</p> <p><strong>UPDATE2</strong></p> <p>Wow one more problem after previous: having a conversion from some Container[T] to T with implicit instance of Container[U] in scope and a function with implicit parameter U leads to 'diverging implicit expansion' too:</p> <pre><code>class A case class Vendor[T](v: T) def f(implicit a: A) {} implicit val vendor = Vendor(new A) implicit def vendorToVal[T](implicit v: Vendor[T]) = v.v f </code></pre> <p>Any hints?</p>
 

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