Don't throw if reply is of error type - just put it in Reply.

src/backends/redis/command.cpp

@@ -43,7 +43,7 @@ namespace redis {
 					PtrToReplyIterator(parReply->element + parReply->elements, &make_redis_reply_type)
 				);
 			case REDIS_REPLY_ERROR:
-				throw RedisError(parReply->str, parReply->len);
+				return ErrorString(parReply->str, parReply->len);
 			default:
 				return Reply();
 			};
@@ -143,9 +143,4 @@ namespace redis {
 	auto Command::zscan (boost::string_ref parKey) -> zscan_range {
 		return zscan_range(zscan_iterator(this, parKey, false), zscan_iterator(this, parKey, true));
 	}
-
-	RedisError::RedisError (const char* parMessage, std::size_t parLength) :
-		std::runtime_error(std::string(parMessage, parLength))
-	{
-	}
 } //namespace redis

src/backends/redis/command.hpp

@@ -90,11 +90,6 @@ namespace redis {
 			LengthArray{ arg_to_bin_safe_length(string_ref(parCommand)), arg_to_bin_safe_length(std::forward<Args>(parArgs))... }.data()
 		);
 	}
-
-	class RedisError : public std::runtime_error {
-	public:
-		RedisError ( const char* parMessage, std::size_t parLength );
-	};
 } //namespace redis
 
 #endif

src/backends/redis/reply.hpp

@@ -25,17 +25,30 @@
 namespace redis {
 	struct Reply;
 
+	class ErrorString {
+	public:
+		ErrorString ( const char* parCStr, std::size_t parLen ) :
+			m_msg(parCStr, parLen)
+		{ }
+		const std::string& message ( void ) const noexcept { return m_msg; }
+
+	private:
+		std::string m_msg;
+	};
+
 	namespace implem {
 		using RedisVariantType = boost::variant<
 			long long,
 			std::string,
-			std::vector<Reply>
+			std::vector<Reply>,
+			ErrorString
 		>;
 	} //namespace implem
 	enum RedisVariantTypes {
 		RedisVariantType_Integer = 0,
 		RedisVariantType_String,
-		RedisVariantType_Array
+		RedisVariantType_Array,
+		RedisVariantType_Error
 	};
 
 	struct Reply : implem::RedisVariantType {
@@ -45,6 +58,7 @@ namespace redis {
 		Reply ( long long parVal ) : base_class(parVal) {}
 		Reply ( std::string&& parVal ) : base_class(std::move(parVal)) {}
 		Reply ( std::vector<Reply>&& parVal ) : base_class(std::move(parVal)) {}
+		Reply ( ErrorString&& parVal ) : base_class(std::move(parVal)) {}
 		~Reply ( void ) noexcept = default;
 	};