Method finish

crates/core/src/alloc/boxed.rs:159–167

Finish this builder and take its boxed slice out. Panics if `self.init_len() != self.capacity()`. Call `self.shrink_to_fit()` if necessary.

(mut self)

        /// Panics if `self.init_len() != self.capacity()`. Call
        /// `self.shrink_to_fit()` if necessary.
        pub fn finish(mut self) -> Box<[T]> {
            assert_eq!(self.init_len(), self.capacity());
            let vec = mem::take(&mut self.vec);
            mem::forget(self);
            let (ptr, len, cap) = vec.into_raw_parts();
            debug_assert_eq!(len, cap);
            let ptr = core::ptr::slice_from_raw_parts_mut(ptr, len);
            unsafe { Box::from_raw(ptr) }
        }

        /// Shrink this builder's allocation such that `self.init_len() ==
        /// self.capacity()`.