move file operations from b3sum to blake3

1 files changed, 3 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index e9ab95e..74aed30 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -81,6 +81,8 @@ no_avx2 = []
 no_avx512 = []
 no_neon = []
 
+file = ["memmap2", "rayon", "std"]
+
 [package.metadata.docs.rs]
 # Document Hasher::update_rayon on docs.rs.
 features = ["rayon", "zeroize"]
@@ -93,6 +95,7 @@ rayon = { version = "1.2.1", optional = true }
 cfg-if = "1.0.0"
 digest = { version = "0.10.1", features = [ "mac" ], optional = true }
 zeroize = { version = "1", default-features = false, features = ["zeroize_derive"], optional = true }
+memmap2 = { version = "0.7.1", optional = true }
 
 [dev-dependencies]
 hex = "0.4.2"