Provide with_cloneable to simplify passing shared services to routes

src/filters/any.rs

@@ -44,6 +44,9 @@ use crate::filter::{Filter, FilterBase, Internal};
 ///         db.contains(&param_id)
 ///     });
 /// ```
+///
+/// Note that [with_cloneable](crate::filters::cloneable::with_cloneable) can be used for
+/// this specific use-case of passing along a cloneable parameter.
 pub fn any() -> impl Filter<Extract = (), Error = Infallible> + Copy {
     Any
 }

src/filters/cloneable.rs

@@ -0,0 +1,30 @@
+//! A filter that matches any route and supplies a clone of the given
+//! [Cloneable](Clone)
+use crate::Filter;
+use std::convert::Infallible;
+
+/// A [`Filter`](Filter) that matches any route and yields a clone
+/// of the given [Cloneable](Clone).
+///
+/// This can be used to supply services or tools to the handling methods.
+///
+/// # Example
+///
+/// ```
+/// use std::sync::Arc;
+/// use warp::Filter;
+///
+/// let state = Arc::new(vec![33, 41]);
+/// let with_state = warp::with_cloneable(state);
+///
+/// let route = warp::path::param()
+///     .and(with_state)
+///     .map(|param_id: u32, db: Arc<Vec<u32>>| {
+///         db.contains(&param_id)
+///     });
+/// ```
+pub fn with_cloneable<C: Clone + Send>(
+    value: C,
+) -> impl Filter<Extract = (C,), Error = Infallible> + Clone {
+    crate::any().map(move || value.clone())
+}

src/filters/mod.rs

@@ -6,6 +6,7 @@
 pub mod addr;
 pub mod any;
 pub mod body;
+pub mod cloneable;
 #[cfg(any(feature = "compression-brotli", feature = "compression-gzip"))]
 pub mod compression;
 pub mod cookie;

src/lib.rs

@@ -121,6 +121,8 @@ pub use self::filters::{
     // any() function
     any::any,
     body,
+    // with_cloneable() function
+    cloneable::with_cloneable,
     cookie,
     // cookie() function
     cookie::cookie,