This shouldn't work.

Cargo.toml

@@ -3,10 +3,13 @@ name = "bit-set"
 version = "0.1.0"
 authors = ["logaritmisk <anders.e.olsson@gmail.com>"]
 
+[features]
+default = ["serde", "rayon"]
+
 [dependencies]
 hashbrown = "0.1"
-rayon = "1.0"
-serde = "1.0"
+rayon = { version = "1.0", optional = true }
+serde = { version = "1.0", optional = true, default-features = false }
 unreachable = "1.0"
 
 [dev-dependencies]
@@ -20,6 +23,3 @@ harness = false
 
 [lib]
 bench = false
-
-[profile.release]
-lto = true