Cargo Features

Cksfv has no features set by default.

[dependencies]
cksfv = { version = "0.1.3", features = ["mmap", "nightly"] }
mmap = memmap
nightly

Enables nightly of crc32fast

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

memmap mmap?