downcast-rs
v2.0.2 GrowingTrait object downcasting support using only safe Rust. It supports type parameters, associated types, and type constraints.
Quick Verdict
- ✓Stable API (2.x for 10+ years)
- ✓Massive adoption (4.4K crates depend on it)
- ✓Tiny footprint (13KB, 0 deps)
- ✓Permissive license (MIT OR Apache-2.0)
Security
Deep Insights
7.8M downloads in the last 30 days (261.4K/day), up 8% from the previous period.
4.4K crates depend on downcast-rs. Strong ecosystem adoption means battle-tested code and long-term stability.
downcast-rs has only 1 owner despite 4.4K dependents. This is a bus-factor concern — consider the implications for long-term support.
The API has been stable (1.x) for over 10 years with 15 releases. This level of maturity means you can depend on it without worrying about breaking changes.
downcast-rs has no external dependencies — minimal supply chain risk and fast compile times.
At 12KB, downcast-rs is lightweight. Small crate size correlates with focused, well-scoped functionality.
Notable dependents include diesel, wayland-backend, valico, tantivy, tantivy-columnar. When high-quality crates choose downcast-rs, it's a strong quality signal.
Health Breakdown
Recency, release consistency, active ratio
Yanked ratio, deps, size, maturity, features
Reverse deps, ownership, ecosystem
Downloads, momentum, growth trend
Docs, repo, license, metadata
Download Trend
Top Dependents
Most downloaded crates that depend on downcast-rs
Version Adoption
Release Timeline
Feature Flags
default =["std", "sync"]
