Add defmt support gated behind a Cargo.toml feature.

Cargo.toml

@@ -17,3 +17,9 @@ rust-version = "1.56.0"
 members = [
     "generate-api",
 ]
+
+[features]
+defmt = ["dep:defmt"]
+
+[dependencies]
+defmt = { version = "1.0.1", optional = true }

generate-api/src/generator.rs

@@ -402,6 +402,7 @@ impl CodeGenerator {
             #![no_std]
 
             #[derive(Debug)]
+            #[cfg_attr(feature = "defmt", derive(defmt::Format))]
             pub struct UnknownLocale;
 
             "#,
@@ -575,6 +576,13 @@ impl CodeGenerator {
                 }}
             }}
 
+            #[cfg(feature = "defmt")]
+            impl defmt::Format for Locale {{
+                fn format(&self, f: defmt::Formatter) {{
+                    defmt::write!(f, "{{:?}}", self);
+                }}
+            }}
+
             impl core::str::FromStr for Locale {{
                 type Err = UnknownLocale;
 

src/lib.rs

@@ -1,6 +1,7 @@
 #![no_std]
 
 #[derive(Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct UnknownLocale;
 
 #[allow(non_snake_case,non_camel_case_types,dead_code,unused_imports)]
@@ -56140,6 +56141,13 @@ impl core::fmt::Debug for Locale {
     }
 }
 
+#[cfg(feature = "defmt")]
+impl defmt::Format for Locale {
+    fn format(&self, f: defmt::Formatter) {
+        defmt::write!(f, "{:?}", self);
+    }
+}
+
 impl core::str::FromStr for Locale {
     type Err = UnknownLocale;