Custom implementation

[recmo]

On 2019-09-11 @recmo wrote in d715d21 “Update merkle-tree”:

Custom implementation

use tempfile::tempfile;

// TODO: Variant of MmapVec where it switched between Vec and Mmap after
//       a treshold size.

#[derive(Debug)] // TODO: Custom implementation
pub struct MmapVec<T: Clone> {
    mmap:     MmapMut,
    length:   usize,
    capacity: usize,
    _t:       PhantomData<T>,

From utils/mmap-vec/src/mmap_vec.rs:18