# `MemoryFile<T>`: Wrap memory mappings over any file-like object
A safe and ergonomic `mmap()` wrapper for arbitrary file-descriptor handles.
__NOTE__: Working release, but still in development.
## Usage
`MemoryFile<T>` can be used to consume any type `T` that implements `AsRawFd`, form a mapping over that file-descriptor, and then unmap the memory before the `T` itself is dropped (which can be a reference or value.)
The `MemoryFile<T>` can also be consumed back into the `T`, unmapping (and optionally syncing) the memory in the process.
### Examples
A function mapping file memory working on arbitrary file-descriptor holding objects.
```rust
pub fn files_equal<T: ?Sized, U: ?Sized>(file1: &T, file2: &U, size: usize) -> io::Result<bool>
where T: AsRawFd,
U: AsRawFd
{
let file1 = MappedFile::try_new(file1, size, Perm::Readonly, Flags::Private)?.with_advice(Advice::Sequential)?;
let file2 = MappedFile::try_new(file2, size, Perm::Readonly, Flags::Private)?.with_advice(Advice::Sequential)?;
Ok(&file1[..] == &file2[..])
}
```
Although, it is probably a better pattern to allow the caller to handle the mapping, and the callee to take any kind of mapping like so:
``` rust
pub fn files_equal<T: ?Sized, U: ?Sized>(file1: &MappedFile<T>, file2: &MappedFile<U>) -> bool
where T: AsRawFd,
U: AsRawFd
{
&file1[..] == &file2[..]
}
```
However, `MappedFile<T>` also implements `Borrow<[u8]>`, so any `&MappedFile<T>` can be passed to any function as `AsRef<[u8]>` too.
# License
MIT