v0.3.0

• Breaking: Raise MSRV to 1.61.0
• Breaking: toml, yaml and json5 are no longer default features (19d9ddc). You now have to manually specify the features you need in Cargo.toml.
• Breaking: env vars set to an empty string, which fail to deserialize/parse/validate are now treated as not set. This is technically a breaking change, but I think this is the expected behavior and shouldn't affect you. (#39)
• ⭐ Add validation feature (#40)
  • #[config(validate = path::to::function)] field: u32 to call the given function during field deserialization.
  • #[config(validate(!s.is_empty(), "user must not be empty"))] user: String is a assert!-style syntax to simple validation checks.
  • Validation can also be added to full structs.
  • See docs and examples for more information!
• Stop including Error::source in the Display output of Error (d454f0957)
• Improve & refactor docs of derive(Config a bit
• Update dependencies (syn to 2.0, heck to 0.5): this shouldn't affect you, except for faster compile times due to smaller dependency tree.