hick v0.2.0

hick v0.2.0 brings mDNS / DNS-SD to RP2040 / Cortex-M0+ (cores without native atomic CAS) and trims the no_std footprint. It bundles everything since v0.1.0 — the no-atomic tier (#40 / #41) and the heapless removal (#43).

Crates

Crate	Version
mdns-proto	0.3.0	⚠️ breaking — heapless removed, no-atomic tier added
hick	0.2.0	facade — adds embassy-no-atomic / smoltcp-no-atomic
hick-reactor	0.2.0	tokio / smol driver
hick-compio	0.2.0	compio (thread-per-core) driver
hick-smoltcp	0.2.0	atomic / no-atomic tiers
hick-embassy	0.2.0	atomic / no-atomic tiers
hick-udp	0.1.0	unchanged
hick-trace	0.1.0	unchanged

Bare-metal without native atomics — RP2040 / Cortex-M0+ (#40, #41)

hick-embassy failed to build for thumbv6m-none-eabi because the protocol core's owned storage pulled smol_str (alloc::sync::Arc) and bytes (atomic refcount) — neither exists without native atomic CAS.

• New no-atomic storage tier in mdns-proto: the same alloc-backed Endpoint, but the refcounted Name / rdata use portable-atomic's Arc (cheap clone via a critical-section impl your binary provides) instead of smol_str + bytes.
• hick-smoltcp / hick-embassy gain atomic (default) vs no-atomic tiers; the hick facade gains smoltcp-no-atomic / embassy-no-atomic. For RP2040:

  hick = { version = "0.2", default-features = false, features = ["embassy-no-atomic"] }

• CI cross-compiles the whole no-atomic stack for thumbv6m-none-eabi, and docs.rs now renders a feature badge on every gated item.

Leaner no_std — dropped the heapless tier (breaking) (#43)

mdns-proto's heapless feature backed owned storage with fixed-capacity inline collections (a 256-byte Name each, fat pools) — a poor fit for no_std stack budgets.

• The rule is now clean: owning a Name / ServiceSpec or building messages needs an allocator (alloc / std / no-atomic); the bare --no-default-features tier is parse-only (the borrowed wire::NameRef). Same stance as quinn-proto.

Upgrading

• mdns-proto: if you enabled features = ["heapless"], switch to alloc (with a global allocator) or no-atomic (cores without native atomics). No-allocator parsing still works via wire::NameRef.
• The driver / facade crates are drop-in at the new 0.2.0 versions.

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MSRV: Rust 1.91 (edition 2024). Licensed under MIT OR Apache-2.0. Full changes: CHANGELOG.