Don't throw InvalidOperationException when native function is missing

Source/Millistream.Streaming/MarketDataFeed.cs

@@ -303,28 +303,14 @@ public bool HandleDelay
         /// <summary>
         /// Gets the intended delay of the current message if delay-mode have been activated by setting the <see cref="HandleDelay"/> property. Note that this is the intended delay of the message and not necessarily the real delay, network latency, server latency and so on are not included.
         /// </summary>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_get_delay function.</exception>
-        public byte Delay
-        {
-            get
-            {
-                Message.ThrowIfNativeFunctionIsMissing(_nativeImplementation.mdf_get_delay, nameof(_nativeImplementation.mdf_get_delay));
-                return _nativeImplementation.mdf_get_delay(_feedHandle);
-            }
-        }
+        /// <remarks>The corresponding native function is mdf_get_delay.</remarks>
+        public byte Delay => _nativeImplementation.mdf_get_delay != default ? _nativeImplementation.mdf_get_delay(_feedHandle) : default;
 
         /// <summary>
         /// Gets the message class of the current received message.
         /// </summary>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_get_mclass function.</exception>
-        public ulong MessageClass
-        {
-            get
-            {
-                Message.ThrowIfNativeFunctionIsMissing(_nativeImplementation.mdf_get_mclass, nameof(_nativeImplementation.mdf_get_mclass));
-                return _nativeImplementation.mdf_get_mclass(_feedHandle);
-            }
-        }
+        /// <remarks>The corresponding native function is mdf_get_mclass.</remarks>
+        public ulong MessageClass => _nativeImplementation.mdf_get_mclass != default ? _nativeImplementation.mdf_get_mclass(_feedHandle) : default;
         #endregion
 
         #region Methods

Source/Millistream.Streaming/Message.ByteOverloads.cs

@@ -50,13 +50,12 @@ public bool AddString(uint tag, ReadOnlySpan<byte> value)
         /// <param name="value">The field value as a memory span that contains a null-terminated sequence of UTF-8 encoded bytes.</param>
         /// <param name="length">The number of bytes in <paramref name="value"/> to be added to the message.</param>
         /// <returns><see langword="true" /> if the field was successfully added, or <see langword="false" /> if the value could not be added (because there was no more memory, the message handle does not contain any messages, or the supplied value is not of the type specified).</returns>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_message_add_string2 function.</exception>
         /// <remarks>The corresponding native function is mdf_message_add_string2.</remarks>
         public bool AddString(uint tag, ReadOnlySpan<byte> value, int length)
         {
-            if (value != null && length < 0)
+            if (_nativeImplementation.mdf_message_add_string2 == default || (value != null && length < 0))
                 return false;
-            ThrowIfNativeFunctionIsMissing(_nativeImplementation.mdf_message_add_string2, nameof(_nativeImplementation.mdf_message_add_string2));
+
             fixed (byte* bytes = value)
                 return _nativeImplementation.mdf_message_add_string2(Handle, tag, (IntPtr)bytes, length) == 1;
         }
@@ -78,7 +77,6 @@ public bool AddString(Field tag, ReadOnlySpan<byte> value) =>
         /// <param name="value">The field value as a memory span that contains a null-terminated sequence of UTF-8 encoded bytes.</param>
         /// <param name="length">The number of bytes in <paramref name="value"/> to be added to the message.</param>
         /// <returns><see langword="true" /> if the field was successfully added, or <see langword="false" /> if the value could not be added (because there was no more memory, the message handle does not contain any messages, or the supplied value is not of the type specified).</returns>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_message_add_string2 function.</exception>
         /// <remarks>The corresponding native function is mdf_message_add_string2.</remarks>
         public bool AddString(Field tag, ReadOnlySpan<byte> value, int length) =>
             AddString((uint)tag, value, length);
@@ -169,13 +167,12 @@ public bool AddList(Field tag, ReadOnlySpan<byte> value) =>
         /// </summary>
         /// <param name="data">A memory span that contains a base64 encoded (serialized) message chain.</param>
         /// <returns><see langword="true" /> if the message chain was successfully deserialized, or <see langword="false" /> if the deserialization failed (if so the current message chain in the message handler is left untouched).</returns>
-        /// <exception cref="InvalidOperationException">The installed version of the native library doesn't include the mdf_message_deserialize function.</exception>
         /// <remarks>The corresponding native function is mdf_message_deserialize.</remarks>
         public bool Deserialize(ReadOnlySpan<byte> data)
         {
-            ThrowIfNativeFunctionIsMissing(_nativeImplementation.mdf_message_deserialize, nameof(_nativeImplementation.mdf_message_deserialize));
             fixed (byte* bytes = data)
-                return _nativeImplementation.mdf_message_deserialize(Handle, (IntPtr)bytes) == 1;
+                return _nativeImplementation.mdf_message_deserialize != default 
+                    && _nativeImplementation.mdf_message_deserialize(Handle, (IntPtr)bytes) == 1;
         }
     }
 }