E0027

语法已弃用。请参考警告消息，了解原因和潜在修复方法。

For example, one of the deprecated usage is using constructors as functions. Instead, partial application should be used to create a function from a constructor.

错误示例

enum Message {
  Add(String)
} derive(Show)

fn perform[T](message : (T) -> Message, produce : () -> T) -> Message {
  message(produce())
}

fn main {
  println(perform(Add, fn() { "Hello, world!" }))
  //              ^^^
  // Warning: Using constructor as function directly is
  // deprecated. Use the partial application syntax instead
}

建议

Migrate the code according to the warning message. In this case, the code should be changed to use the partial application syntax.

// ...
fn main {
  println(perform(Add(_), fn() { "Hello, world!" }))
}