From b4be008ea958a423636c098027881dc1b93b6983 Mon Sep 17 00:00:00 2001
From: Paul Bender <pebender@gmail.com>
Date: Thu, 9 Oct 2025 19:31:43 -0700
Subject: [PATCH] Add defmt support gated behind a feature flag.

---
 Cargo.toml                        |  6 ++++++
 embedded-storage-async/Cargo.toml |  4 ++++
 src/iter.rs                       |  4 ++--
 src/nor_flash.rs                  | 12 ++++++++++++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index c851083..30b9aa2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,3 +13,9 @@ documentation = "https://docs.rs/embedded-storage"
 readme = "README.md"
 keywords = ["storage"]
 categories = ["embedded", "hardware-support", "no-std"]
+
+[features]
+defmt = ["dep:defmt"]
+
+[dependencies]
+defmt = { version = "1.0.1", optional = true }
diff --git a/embedded-storage-async/Cargo.toml b/embedded-storage-async/Cargo.toml
index dcf138f..885b443 100644
--- a/embedded-storage-async/Cargo.toml
+++ b/embedded-storage-async/Cargo.toml
@@ -17,5 +17,9 @@ readme = "README.md"
 keywords = ["storage"]
 categories = ["embedded", "hardware-support", "no-std"]
 
+[features]
+defmt = ["dep:defmt", "embedded-storage/defmt"]
+
 [dependencies]
 embedded-storage = { version = "0.3.1", path = "../" }
+defmt = { version = "1.0.1", optional = true }
diff --git a/src/iter.rs b/src/iter.rs
index 3b5c102..1eb8799 100644
--- a/src/iter.rs
+++ b/src/iter.rs
@@ -19,7 +19,7 @@ where
 	I: Iterator<Item = R>,
 {
 	/// Obtain an [`OverlapIterator`] over a subslice of `memory` that overlaps with the region in `self`
-	fn overlaps(self, memory: &'a [u8], base_address: u32) -> OverlapIterator<R, I>;
+	fn overlaps(self, memory: &'a [u8], base_address: u32) -> OverlapIterator<'a, R, I>;
 }
 
 impl<'a, R, I> Iterator for OverlapIterator<'a, R, I>
@@ -54,7 +54,7 @@ where
 	R: Region,
 	I: Iterator<Item = R>,
 {
-	fn overlaps(self, memory: &'a [u8], base_address: u32) -> OverlapIterator<R, I> {
+	fn overlaps(self, memory: &'a [u8], base_address: u32) -> OverlapIterator<'a, R, I> {
 		OverlapIterator {
 			memory,
 			regions: self,
diff --git a/src/nor_flash.rs b/src/nor_flash.rs
index 447bd1a..32807b6 100644
--- a/src/nor_flash.rs
+++ b/src/nor_flash.rs
@@ -4,11 +4,22 @@ use crate::{iter::IterableByOverlaps, ReadStorage, Region, Storage};
 ///
 /// NOR flash implementations must use an error type implementing this trait. This permits generic
 /// code to extract a generic error kind.
+#[cfg(not(feature = "defmt"))]
 pub trait NorFlashError: core::fmt::Debug {
 	/// Convert a specific NOR flash error into a generic error kind.
 	fn kind(&self) -> NorFlashErrorKind;
 }
 
+/// NOR flash errors.
+///
+/// NOR flash implementations must use an error type implementing this trait. This permits generic
+/// code to extract a generic error kind.
+#[cfg(feature = "defmt")]
+pub trait NorFlashError: core::fmt::Debug + defmt::Format {
+	/// Convert a specific NOR flash error into a generic error kind.
+	fn kind(&self) -> NorFlashErrorKind;
+}
+
 impl NorFlashError for core::convert::Infallible {
 	fn kind(&self) -> NorFlashErrorKind {
 		match *self {}
@@ -26,6 +37,7 @@ pub trait ErrorType {
 /// NOR flash implementations must map their error to those generic error kinds through the
 /// [`NorFlashError`] trait.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 #[non_exhaustive]
 pub enum NorFlashErrorKind {
 	/// The arguments are not properly aligned.