Add non-empty string and collection types for API boundary validation

Cargo.toml

@@ -23,6 +23,7 @@ figment = { version = "0.10.0", features = [
     "test",
     "yaml",
 ], optional = true }
+nonempty = { version = "0.10.0", features = ["serialize"], optional = true }
 paste = { version = "1.0.0", optional = true }
 reqwest = { version = "0.13.0", optional = true }
 schemars = { version = "1.2.0", optional = true }
@@ -44,6 +45,7 @@ time = ["dep:time"]
 schemars = ["dep:schemars", "schemars/url2"]
 serde = ["dep:serde", "dep:paste"]
 base_url = ["dep:url", "dep:thiserror", "dep:serde"]
+non_empty = ["dep:nonempty", "dep:serde", "dep:thiserror"]
 
 [lints.rust]
 dead_code = "warn"

src/lib.rs

@@ -2,7 +2,6 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-#![cfg_attr(all(doc, not(doctest)), feature(doc_auto_cfg))]
 //! This crate consists of incohesive generic types and functions that are
 //! needed in almost every crate but are so small that making a separate crate
 //! for them is too much.
@@ -16,6 +15,9 @@
 //! See [`LevelFilter`], [`BaseUrl`] and [`duration`] for useful wrapper types
 //! to use in your `serde`-based configs.
 //!
+//! See [`NonEmptyString`], [`TrimmedNonEmptyString`], and [`NonEmptyVec`] for
+//! non-empty types that enforce invariants at deserialization time.
+//!
 //! Enable `schemars` feature to get [`schemars::JsonSchema`] impls for
 //! "config-helper" types to generate config schemas (for documentation and
 //! validation purposes).
@@ -35,13 +37,19 @@ pub mod config;
 pub mod duration;
 #[cfg(feature = "level_filter")]
 mod level_filter;
+#[cfg(feature = "non_empty")]
+pub mod non_empty;
 #[cfg(feature = "reqwest")]
 pub mod reqwest;
 
 #[cfg(feature = "base_url")]
 pub use base_url::{BaseUrl, BaseUrlParseError};
 #[cfg(feature = "level_filter")]
 pub use level_filter::LevelFilter;
+#[cfg(feature = "non_empty")]
+pub use non_empty::{
+	nonempty, NonEmpty, NonEmptyError, NonEmptyString, NonEmptyVec, TrimmedNonEmptyString,
+};
 
 /// Generic combinators on polymorphic unconstrained types that `std` lacks.
 ///