Everything working under clang

src/deserialize.cxx

@@ -8,7 +8,7 @@ export module modbus:deserialize;
 import :function;
 import :error;
 
-namespace modbus::impl {
+export namespace modbus::impl {
 
 /// Check if length is sufficient.
 [[nodiscard]] inline auto check_length(std::size_t actual, std::size_t needed) -> std::error_code {

src/modbus.cxx

@@ -4,5 +4,8 @@ export import :client;
 export import :error;
 export import :packet;
 export import :deserialize;
+export import :serialize;
 export import :default_handler;
-export import :server;
+export import :server;
+export import :tcp;
+export import :function;

src/packet.cxx

@@ -32,8 +32,9 @@ export module modbus:packet;
 import :deserialize;
 import :serialize;
 import :function;
+import :tcp;
 
-namespace modbus {
+export namespace modbus {
 namespace request {
 struct read_coils;
 struct read_discrete_inputs;

src/serialize.cxx

@@ -7,7 +7,7 @@ module;
 export module modbus:serialize;
 import :function;
 
-namespace modbus::impl {
+export namespace modbus::impl {
 
 /// Convert a boolean to a uint16 Modbus representation.
 inline auto bool_to_uint16(bool value) -> std::uint16_t {

src/tcp.cxx

@@ -11,7 +11,7 @@ namespace modbus {
 
 /// Modbus/TCP application protocol (MBAP) header.
 #pragma pack(push, 1)
-struct tcp_mbap {
+export struct tcp_mbap {
  std::uint16_t transaction;
  std::uint16_t protocol = 0; // 0 for modbus.
  std::uint16_t length;

tests/helpers/mbpoll_request_encoding_sniffer.cpp

@@ -3,6 +3,7 @@
 // Used to generate test data from known working modbus clients
 // fe mbpoll
 
+#include <exception>
 #include <asio.hpp>
 #include <iostream>
 

tests/serialization.cxx

@@ -1,6 +1,9 @@
 #include <array>
 
 #include <boost/ut.hpp>
+#include <span>
+
+import modbus;
 
 void print_bytes(std::span<uint8_t> data) {
  for (auto& k : data) {