Crate pages[−][src]
Expand description
A dynamically-sized heap-backed data page. Comprises a user-chosen header and data array packed into a single allocation.
Example
use pages::Page; // A really crappy replacement for Box<Option<usize>> struct Maybe(Page::<bool, usize>); impl Maybe { fn new() -> Self { Maybe(Page::new(false, 1)) } fn put(&mut self, value: usize) { *self.0.header_mut() = true; // occupied let item: *mut usize = self.0.data_mut()[0].as_mut_ptr(); unsafe { item.write(value); } } fn get(&mut self) -> Option<usize> { if !(*self.0.header()) { return None; } let item: *mut usize = self.0.data_mut()[0].as_mut_ptr(); *self.0.header_mut() = false; // free Some(unsafe { *item }) } } let mut maybe = Maybe::new(); assert_eq!(maybe.get(), None); maybe.put(42); assert_eq!(maybe.get(), Some(42));