Decision Workspace
downcast-rs vs extension-trait vs extern-trait
Side-by-side comparison of Rust crates
65
downcast-rs
growingv2.0.2
Trait object downcasting support using only safe Rust. It supports type parameters, associated types, and type constraints.
57
extension-trait
growingv1.0.2
Macro to declare extension traits
55
extern-trait
experimentalv0.4.1
Opaque types for traits using static dispatch
Core Metrics
| downcast-rs | extension-trait | extern-trait | |
|---|---|---|---|
| Health Score | 65 | 57 | 55 |
| Total Downloads | 102.2M | 459.8K | 14.9K |
| 30d Downloads | 7.5M | 33.5K | 3.3K |
| Dependents | 4.4K | 354 | 23 |
| Releases | 15 | 11 | 6 |
| Last Updated | 207d ago | 1103d ago | 52d ago |
| Age | 10y 3m | 8y 4m | 11m |
Health Breakdown
downcast-rs
Maintenance
8
Quality
23
Community
14
Popularity
8
Documentation
12
extension-trait
Maintenance
5
Quality
20
Community
12
Popularity
7
Documentation
13
extern-trait
Maintenance
16
Quality
14
Community
10
Popularity
5
Documentation
10
Technical Details
| downcast-rs | extension-trait | extern-trait | |
|---|---|---|---|
| Version | 2.0.2 | 1.0.2 | 0.4.1 |
| Stable (≥1.0) | ✓ Yes | ✓ Yes | ✗ No |
| License | MIT OR Apache-2.0 | MIT OR Apache-2.0 | MIT OR Apache-2.0 |
| Dependencies | 0 | 3 | 2 |
| Crate Size | 13KB | 8KB | 14KB |
| Features | 3 | 0 | 0 |
| Yanked % | 0.0% | 0.0% | 0.0% |
| Edition | 2021 | 2021 | 2024 |
| MSRV | 1.56 | — | — |
| Owners | 1 | 1 | 1 |
Links
Quick Verdict
- •downcast-rs leads with a health score of 65/100, but none of the options score above 80.
- •downcast-rs is depended on by 4.4K crates — strongest ecosystem trust.
- •⚠ extension-trait has not been updated in over a year.
- •extern-trait is pre-1.0 — API may change.