How do I create an empty Guava ImmutableList?

Question

I can create a Guava ImmutableList with the of method, and will get the correct generic type based on the passed objects:

Foo foo = new Foo(); ImmutableList.of(foo); 

However, the of method with no parameters cannot infer the generic type and creates an ImmutableList<Object>.

How can I create an empty ImmutableList to satisfy List<Foo>?

Answer 1

If you assign the created list to a variable, you don't have to do anything:

ImmutableList<Foo> list = ImmutableList.of(); 

In other cases where the type can't be inferred, you have to write ImmutableList.<Foo>of() as @zigg says.

Answer 2

ImmutableList.<Foo>of() will create an empty ImmutableList with generic type Foo. Though the compiler can infer the generic type in some circumstances, like assignment to a variable, you'll need to use this format (as I did) when you're providing the value for a function argument.