Cargo Features

BitFlags has no features set by default.

bitflags = { version = "2.4.1", features = ["std", "example_generated", "rustc-dep-of-std", "serde", "bytemuck", "arbitrary"] }

Affects bitflags::example_generated

rustc-dep-of-std = compiler_builtins, core

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features.

serde implicit feature

Affects external::serde

bytemuck implicit feature
core rustc-dep-of-std?

Enables rustc-std-workspace-core

compiler_builtins rustc-dep-of-std?

With default (compiler-builtins)

arbitrary implicit feature

Affects external::arbitrary