@@ -20,10 +20,20 @@
 
 /** @file */
 
 @class OFTLSStream;
 
+/**
+ * @brief An enum representing an error of an OFTLSStream.
+ */
+typedef enum {
+	/** @brief An unknown error. */
+	OFTLSStreamErrorCodeUnknown,
+	/** @brief Initialization of the TLS context failed. */
+	OFTLSStreamErrorCodeInitializationFailed
+} OFTLSStreamErrorCode;
+
 /**
  * @protocol OFTLSStreamDelegate OFTLSStream.h ObjFW/OFTLSStream.h
  *
  * A delegate for OFTLSStream.
  */
@@ -108,11 +118,12 @@
  * @param stream The stream to use as underlying stream. Must not be closed
  *		 before the TLS stream is closed.
  * @return An initialized TLS stream
  */
 - (instancetype)initWithStream: (OFStream <OFReadyForReadingObserving,
-				     OFReadyForWritingObserving> *)stream;
+				     OFReadyForWritingObserving> *)stream
+    OF_DESIGNATED_INITIALIZER;
 
 /**
  * @brief Asynchronously performs the TLS client handshake for the specified
  *	  host and calls the delegate afterwards.
  *
@@ -147,10 +158,19 @@
  * This can be set to a class that is always used for OFTLSStream. This is
  * useful to either force a specific implementation or use one that ObjFW does
  * not know about.
  */
 extern Class OFTLSStreamImplementation;
+
+/**
+ * @brief Returns a string description for the TLS stream error code.
+ *
+ * @param errorCode The error code to return the description for
+ * @return A string description for the TLS stream error code
+ */
+extern OFString *OFTLSStreamErrorCodeDescription(
+    OFTLSStreamErrorCode errorCode);
 #ifdef __cplusplus
 }
 #endif
 
 OF_ASSUME_NONNULL_END