Cargo Features

futures-core = { version = "0.3.30", default-features = false, features = ["std", "alloc", "unstable", "cfg-target-has-atomic", "portable-atomic"] }
default = std

The std feature is set by default whenever futures-core is added without default-features = false somewhere in the dependency tree.

std default = alloc
alloc std

Affects future::BoxFuture, future::LocalBoxFuture, stream::BoxStream, stream::LocalBoxStream


These features are no longer used.
TODO: remove in the next major version.


Features from optional dependencies

portable-atomic implicit feature

Enables portable-atomic


Portable atomic types including support for 128-bit atomics, atomic float, etc