Marcono1234 commented on pull request #451:
URL: https://github.com/apache/logging-log4j2/pull/451#issuecomment-751490879
> and you can say that any method is 'not type-safe' if it is declared in
the patten `<T> T foo()`.
And I will say this 😄
Though to clarify, the issue I am having with this is that the return type
is not bound, i.e. none of the parameters of method (in this case there are no
parameters) refer to this type parameter. Using type parameters which are bound
as return type is perfectly fine.
Personally I think such constructs should be used very sparingly and only
where it is absolutely necessary. There is a reason why the compiler complains
about the implementation of this method in `AbstractLogger` and you have to use
`@SuppressWarnings("unchecked")` to suppress that warning.
The problem with these unbound return types is that the user of the API
might not even notice it because to them it just looks like any other method.
But is allows them to write something like the following which won't cause any
errors during compile time, not even any warnings, but will break during
runtime:
```java
interface MyCustomMessageFactory extends MessageFactory {
}
Logger logger = LogManager.getLogger();
// Compiles without any warnings or errors
MyCustomMessageFactory f = logger.getMessageFactory();
```
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