zio.test.Eql.scala Maven / Gradle / Ivy
/*
* Copyright 2019-2022 John A. De Goes and the ZIO Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package zio.test
import zio.stacktracer.TracingImplicits.disableAutoTrace
import scala.annotation.implicitNotFound
/**
* A value of type `Eql[A, B]` provides implicit evidence that two values with
* types `A` and `B` could potentially be equal, that is, that `A` is a subtype
* of `B` or `B` is a subtype of `A`.
*/
@implicitNotFound(
"This operation assumes that values of types ${A} and ${B} could " +
"potentially be equal. However, ${A} and ${B} are unrelated types, so " +
"they cannot be equal."
)
sealed abstract class Eql[A, B]
object Eql extends EqlLowPriority {
implicit final def eqlSubtype1[A <: B, B]: Eql[A, B] = new Eql[A, B] {}
}
private[test] sealed abstract class EqlLowPriority {
implicit final def eqlSubtype2[A, B <: A]: Eql[A, B] = new Eql[A, B] {}
}