Learn how to implement a multi-scheme password hashing system in Rust for web applications. Explore the implementation of HMAC/SHA512 as Scheme 1 and Argon2 as Scheme 2, featuring seamless auto-upgrade between schemes and static dispatch. Follow along as the tutorial covers base hash and validation functions, scheme infrastructure, web login implementation, and the transition from dynamic to static dispatch. Gain insights into creating a secure and efficient password system for Rust web applications through this comprehensive coding demonstration.