条件隐式定义Scala [英] Conditional Implicit Definitions Scala

问题描述

我必须解决这个问题，但是我找不到正确的答案.

I have to solve this quinz but i can't find the correct answer.

trait Physics {
  implicit def air: Gaz,
  implicit def condense(implicit gaz: Gaz): Liquid,
  implicit def freeze(implicit liquid: Liquid): Solid

  implicitly[Solid]
}

您可以使用显式编写的推断参数重写最后一行吗?

Can you rewrite the last line with the inferred parameter explicitly written?

提示:应该看起来像 隐式[固体](...

Hint: It should look like implicitly[Solid](...

非常感谢您！

推荐答案

这里是一个提示:首先考虑implicitly只是一种与其他方法一样的方法

Here is a hint: first consider implicitly is just a method like any other

def implicitly[T](implicit e: T): T = e

让我们删除关键字implicit这样

def implicitly[T](e: T): T = e

给出implicitly只是一个带有参数的方法，请考虑如何使编译器满意并让方法implicitly返回Solid?

Given implicitly is just a method taking arguments, think about what would you have to do to make compiler happy and have method implicitly return a Solid?

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