unsafe

Why does sun.misc.Unsafe exist, and how can it be used in the real world?

examples VM “intrinsification.” ie CAS (Compare-And-Swap) used in Lock-Free Hash Tables eg:sun.misc.Unsafe.compareAndSwapInt it can make real JNI calls into native code that contains special instructions for CAS read more about CAS here http://en.wikipedia.org/wiki/Compare-and-swap The sun.misc.Unsafe functionality of the host VM can be used to allocate uninitialized objects and then interpret the constructor invocation as any … Read more

How do I get an owned value out of a `Box`?

Dereference the value: fn unbox<T>(value: Box<T>) -> T { *value } There’s a nightly associated function into_inner you can use as well: #![feature(box_into_inner)] fn unbox<T>(value: Box<T>) -> T { Box::into_inner(value) } Way back in pre-1.0 Rust, heap-allocated values were very special types, and they used the sigil ~ (as in ~T). Along the road to … Read more

How can I use pointers in Java?

All objects in Java are references and you can use them like pointers. abstract class Animal {… } class Lion extends Animal {… } class Tiger extends Animal { public Tiger() {…} public void growl(){…} } Tiger first = null; Tiger second = new Tiger(); Tiger third; Dereferencing a null: first.growl(); // ERROR, first is … Read more