Calling Enum.<T>valueOf() giving unchecked cast warning, despite T being declared <T extends Enum<T>>
enums, generics, java
Solution
You should be calling `getDeclaringClass()`, which will also fix the generics issues (it is specified to return `Class<T>`). Calling `getClass()` on an enum constant with its own methods defined can actually return a different class from the enum type.
Problem
This has to be something small, but I'm not getting it. Why is this causing an unchecked cast compiler warning, when it has the exact same generic declaration as in `Enum`'s `valueOf`? ``` public static final <T extends Enum<T>> Enum toValue(T for_value, String value) { try { return Enum.<T>valueOf((Class<T>)for_value.getClass(), value); } catch(RuntimeException rx) { throw new IllegalArgumentException(value); } } ``` Compiler warning: ``` R:\jeffy\programming\sandbox\xbnjava\xbn\util\EnumUtil.java:92: warning: [unchecked] unchecked cast Enum.<T>valueOf((Class<T>)for_value.getClass(), value); ^ required: Class<T> found: Class<CAP#1> where T is a type-variable: T extends Enum<T> declared in method <T>toValue(T,String,String) where CAP#1 is a fresh type-variable: CAP#1 extends Enum from capture of ? extends Enum R:\jeffy\programming\sandbox\xbnjava\xbn\util\EnumUtil.java:98: error: missing return statement } ^ 1 error 1 warning ``` It also happens in one or both of the generics are removed from the function call, such as ``` Enum.valueOf(for_value.getClass(), value); ``` This is the closest question I've found: Enum.valueOf throws a warning for unknown type of class that extends Enum?. This enum's type is known.