fix protocol warnings

Author: rnro

Sources/StructuredFieldValues/Decoder/BareItemDecoder.swift

@@ -97,30 +97,6 @@ extension BareItemDecoder: SingleValueDecodingContainer {
         return bool
     }
 
-    func decode(_: Data.Type) throws -> Data {
-        guard case .undecodedByteSequence(let data) = self.item else {
-            throw StructuredHeaderError.invalidTypeForItem
-        }
-
-        guard let decoded = Data(base64Encoded: data) else {
-            throw StructuredHeaderError.invalidByteSequence
-        }
-
-        return decoded
-    }
-
-    func decode(_: Decimal.Type) throws -> Decimal {
-        guard case .decimal(let pseudoDecimal) = self.item else {
-            throw StructuredHeaderError.invalidTypeForItem
-        }
-
-        return Decimal(
-            sign: pseudoDecimal.mantissa > 0 ? .plus : .minus,
-            exponent: Int(pseudoDecimal.exponent),
-            significand: Decimal(pseudoDecimal.mantissa.magnitude)
-        )
-    }
-
     func decodeNil() -> Bool {
         // Items are never nil.
         false
@@ -186,3 +162,29 @@ extension BareItemDecoder: SingleValueDecodingContainer {
         return result
     }
 }
+
+extension BareItemDecoder {
+    func decode(_: Data.Type) throws -> Data {
+        guard case .undecodedByteSequence(let data) = self.item else {
+            throw StructuredHeaderError.invalidTypeForItem
+        }
+
+        guard let decoded = Data(base64Encoded: data) else {
+            throw StructuredHeaderError.invalidByteSequence
+        }
+
+        return decoded
+    }
+
+    func decode(_: Decimal.Type) throws -> Decimal {
+        guard case .decimal(let pseudoDecimal) = self.item else {
+            throw StructuredHeaderError.invalidTypeForItem
+        }
+
+        return Decimal(
+            sign: pseudoDecimal.mantissa > 0 ? .plus : .minus,
+            exponent: Int(pseudoDecimal.exponent),
+            significand: Decimal(pseudoDecimal.mantissa.magnitude)
+        )
+    }
+}

Sources/StructuredFieldValues/Encoder/StructuredFieldValueEncoder.swift

@@ -280,21 +280,6 @@ extension _StructuredFieldEncoder: SingleValueEncodingContainer {
         try self._encodeFixedWidthInteger(value)
     }
 
-    func encode(_ data: Data) throws {
-        let encoded = data.base64EncodedString()
-        try self.currentStackEntry.storage.insertBareItem(.undecodedByteSequence(encoded))
-    }
-
-    func encode(_ data: Decimal) throws {
-        let significand = (data.significand.magnitude as NSNumber).intValue  // Yes, really.
-        guard let exponent = Int8(exactly: data.exponent) else {
-            throw StructuredHeaderError.invalidIntegerOrDecimal
-        }
-
-        let pd = PseudoDecimal(mantissa: significand * (data.isSignMinus ? -1 : 1), exponent: Int(exponent))
-        try self.currentStackEntry.storage.insertBareItem(.decimal(pd))
-    }
-
     func encode<T>(_ value: T) throws where T: Encodable {
         switch value {
         case let value as UInt8:
@@ -348,6 +333,23 @@ extension _StructuredFieldEncoder: SingleValueEncodingContainer {
     }
 }
 
+extension _StructuredFieldEncoder {
+    func encode(_ data: Data) throws {
+        let encoded = data.base64EncodedString()
+        try self.currentStackEntry.storage.insertBareItem(.undecodedByteSequence(encoded))
+    }
+
+    func encode(_ data: Decimal) throws {
+        let significand = (data.significand.magnitude as NSNumber).intValue  // Yes, really.
+        guard let exponent = Int8(exactly: data.exponent) else {
+            throw StructuredHeaderError.invalidIntegerOrDecimal
+        }
+
+        let pd = PseudoDecimal(mantissa: significand * (data.isSignMinus ? -1 : 1), exponent: Int(exponent))
+        try self.currentStackEntry.storage.insertBareItem(.decimal(pd))
+    }
+}
+
 extension _StructuredFieldEncoder {
     // This extension sort-of corresponds to the unkeyed encoding container: all of
     // these methods are called from there.