Crate features / heapless
Feature flags · heapless 0.9.3 · from crates.io 2026-10-24
heapless features: what each one does, and the line to copy
Short answerheapless 0.9.3 has 12 features. Nothing is on by default: turn on what you use. It needs Rust 1.87 or newer.
Pick features
Every feature
| Feature | In default | Turns on |
|---|---|---|
alloc | nothing else (a switch the code checks) | |
bytes | dep:bytes | |
defmt | dep:defmt | |
embedded-io-v0.7 | dep:embedded-io | |
mpmc_large | nothing else (a switch the code checks) | |
nightly | nothing else (a switch the code checks) | |
portable-atomic | dep:portable-atomic | |
portable-atomic-critical-section | dep:portable-atomic, portable-atomic, portable-atomic?/critical-section | |
portable-atomic-unsafe-assume-single-core | dep:portable-atomic, portable-atomic, portable-atomic?/unsafe-assume-single-core | |
serde | dep:serde_core | |
ufmt | dep:ufmt, dep:ufmt-write | |
zeroize | dep:zeroize |
dep:x turns on the optional dependency x; x/y turns on feature y of dependency x (with ?, only if x is already on).
MSRV history
The minimum Rust version heapless declares (rust-version), and the release that changed it:
- 0.9.2 (2025-11-12): Rust 1.87
Stuck on an older compiler? Pin the last version that supports it, for example cargo update -p heapless --precise <version>, or use resolver 3, which picks compatible versions for you.
More on heapless
Real downloads, dependents and alternatives: heapless crate data (576.7K real downloads a day, 1,162 dependents).
Security record: heapless advisories.
docs.rs feature list · crates.io · license MIT OR Apache-2.0 · edition 2021
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