ci: fix new lifetime lint

This lint appears when running the stable compiler, not just clippy. We
don't pin the stable compiler version, so this has started showing up
in CI, which is a bit noisy.

Author: apoelstra

src/descriptor/mod.rs

@@ -294,7 +294,7 @@ impl<Pk: MiniscriptKey> Descriptor<Pk> {
     ///
     /// If the descriptor is not a Taproot descriptor, **or** if the descriptor is a
     /// Taproot descriptor containing only a keyspend, returns an empty iterator.
-    pub fn tap_tree_iter(&self) -> tr::TapTreeIter<Pk> {
+    pub fn tap_tree_iter(&self) -> tr::TapTreeIter<'_, Pk> {
         if let Descriptor::Tr(ref tr) = self {
             if let Some(tree) = tr.tap_tree() {
                 return tree.leaves();

src/descriptor/tr/mod.rs

@@ -108,7 +108,7 @@ impl<Pk: MiniscriptKey> Tr<Pk> {
     ///
     /// The yielded elements include the Miniscript for each leave as well as its depth
     /// in the tree, which is the data required by PSBT (BIP 371).
-    pub fn leaves(&self) -> TapTreeIter<Pk> {
+    pub fn leaves(&self) -> TapTreeIter<'_, Pk> {
         match self.tree {
             Some(ref t) => t.leaves(),
             None => TapTreeIter::empty(),

src/descriptor/tr/spend_info.rs

@@ -181,7 +181,7 @@ impl<Pk: ToPublicKey> TrSpendInfo<Pk> {
     /// This yields the same leaves in the same order as [`super::Tr::leaves`] on the original
     /// [`super::Tr`]. However, in addition to yielding the leaves and their depths, it also
     /// yields their scripts, leafhashes, and control blocks.
-    pub fn leaves(&self) -> TrSpendInfoIter<Pk> {
+    pub fn leaves(&self) -> TrSpendInfoIter<'_, Pk> {
         TrSpendInfoIter {
             spend_info: self,
             index: 0,

src/descriptor/tr/taptree.rs

@@ -53,7 +53,7 @@ impl<Pk: MiniscriptKey> TapTree<Pk> {
     ///
     /// The yielded elements include the Miniscript for each leave as well as its depth
     /// in the tree, which is the data required by PSBT (BIP 371).
-    pub fn leaves(&self) -> TapTreeIter<Pk> { TapTreeIter::from_tree(self) }
+    pub fn leaves(&self) -> TapTreeIter<'_, Pk> { TapTreeIter::from_tree(self) }
 
     /// Converts keys from one type of public key to another.
     pub fn translate_pk<T>(

src/miniscript/iter.rs

@@ -18,12 +18,12 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Miniscript<Pk, Ctx> {
     /// Creates a new [Iter] iterator that will iterate over all [Miniscript] items within
     /// AST by traversing its branches. For the specific algorithm please see
     /// [Iter::next] function.
-    pub fn iter(&self) -> Iter<Pk, Ctx> { Iter::new(self) }
+    pub fn iter(&self) -> Iter<'_, Pk, Ctx> { Iter::new(self) }
 
     /// Creates a new [PkIter] iterator that will iterate over all plain public keys (and not
     /// key hash values) present in [Miniscript] items within AST by traversing all its branches.
     /// For the specific algorithm please see [PkIter::next] function.
-    pub fn iter_pk(&self) -> PkIter<Pk, Ctx> { PkIter::new(self) }
+    pub fn iter_pk(&self) -> PkIter<'_, Pk, Ctx> { PkIter::new(self) }
 
     /// Enumerates all child nodes of the current AST node (`self`) and returns a `Vec` referencing
     /// them.

src/policy/concrete.rs

@@ -192,7 +192,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
     /// Since this splitting might lead to exponential blow-up, we constrain the number of
     /// leaf-nodes to [`MAX_COMPILATION_LEAVES`].
     #[cfg(feature = "compiler")]
-    fn tapleaf_probability_iter(&self) -> TapleafProbabilityIter<Pk> {
+    fn tapleaf_probability_iter(&self) -> TapleafProbabilityIter<'_, Pk> {
         TapleafProbabilityIter { stack: vec![(1.0, self)] }
     }
 

src/primitives/threshold.rs

@@ -217,7 +217,7 @@ impl<T, const MAX: usize> Threshold<T, MAX> {
     pub fn into_data(self) -> Vec<T> { self.inner }
 
     /// Passthrough to an iterator on the underlying vector.
-    pub fn iter(&self) -> core::slice::Iter<T> { self.inner.iter() }
+    pub fn iter(&self) -> core::slice::Iter<'_, T> { self.inner.iter() }
 }
 
 impl<T> Threshold<T, 0> {