Unbox | The easy to use Swift JSON decoder | JSON Processing library

Assuming that you're getting a byte slice from Javascript, you should be able to use ndarray::ArrayView to create a borrowed view into the data:

https://docs.rs/ndarray/0.15.1/ndarray/type.ArrayView.html#impl

I can't find a proper solution. It could be just a bug introduced in one of the latest versions and nobody has come across this problem with value types so far. Actually, I tried

Wrapping types are not on the heap because they box a primitive type but because they are objects. Primitive types can live on the stack, as local variables, or on the heap, as member variables.

What happens in your example is:

• Long l2 = cls.myLong; assigns the reference of the object behind class.myLong to l2, or in other words: l2 now references the same object as class.myLong.
• l2 += 5; unboxes the object referenced by l2, adds 5 to the value, wraps the result in a new instance of Long and assigns the reference of that new instance to l2, or in other words: l2 now references a new object, which wraps the result.

Imagine this example code:

If you remove the method add(int a, long... b) you will find that your code won't compile because the remaining method add(int a, Long b) cannot be called with add(1, 2) because 2 is an int and a primitive int cannot be boxed into a Long. Likewise, the statement Long a = 2; is invalid. Therefore the only matching candidate is add(int a, long... b).

I agree with the first two comments. Also, it's not a generics problem, it's just that the method doesn't work because it's not supposed to work because the boxing assumption you concluded doesn't apply here.

Autoboxing and Unboxing are supplied for some of the Number types but not all. See table below: https://docs.oracle.com/javase/tutorial/java/data/autoboxing.html

So while this works the way you expect (because both types are in the supported table):

mainly because I believe x needs to be bound to {. during the creation of the verb.

If creating a verb with an input is the key, shouldn't you use an adverb?

I don't quite know if this is what you are looking for, but you could make the SendAndReceive generic on the sender and receiver:

if you have a primitive boolean variable, then assign true or false to avoid performing the unboxing.

if you have a wrapper Boolean variable, then use Boolean.TRUE or Boolean.FALSE to avoid performing boxing and/or instantiation of a new object.

The ST monad is for when you want to take some immutable data, make it temporarily mutable, do something with it, and make it immutable again. In particular, there is no way to return a mutable result from the ST monad (by design).

In particular, STVector is mutable, so it can never leave the ST monad. So there is no way to "print out" new0. You would have to convert it to something immutable to return it out of the ST monad.

If you're wanting to mutate something, print it out, mutate it a bit more, print it out, etc., you probably want the IO monad. The ST monad is for making something temporarily mutable, to eventually produce an ordinary immeduate result.

Regarding the s type variable: It's a slight hack that enforces the property that mutable data cannot leave ST. The runST function requires an action that works for every possible choice of s. This means it's impossible to return anything that contains s. Since all the mutable stuff has s in its type signature, this enforces our guarantee.