🚸 Add fail tests for field not being in message

Problem:
- When a field is not in a message, trying to access it can give an help
  message from inside `stdx::tuple` instead of a nicer message.

Solution:
- Give a nicer help message when trying to access a named field that isn't in a
  message.

Author: elbeno

include/msg/message.hpp

@@ -198,7 +198,10 @@ template <stdx::ct_string Name, typename... Fields> class msg_access {
     using FieldsTuple =
         decltype(stdx::make_indexed_tuple<name_for>(Fields{}...));
 
-    template <typename Field, stdx::range R> constexpr static auto check() {
+    template <typename N, stdx::range R> constexpr static auto check() {
+        static_assert((std::is_same_v<N, name_for<Fields>> or ...),
+                      "Field does not belong to this message!");
+        using Field = field_t<N>;
         constexpr auto belongs = (std::is_same_v<typename Field::field_id,
                                                  typename Fields::field_id> or
                                   ...);
@@ -209,20 +212,20 @@ template <stdx::ct_string Name, typename... Fields> class msg_access {
 
     template <stdx::range R, some_field_value V>
     constexpr static auto set1(R &&r, V v) -> void {
+        check<name_for<V>, std::remove_cvref_t<R>>();
         using Field = field_t<name_for<V>>;
-        check<Field, std::remove_cvref_t<R>>();
         Field::insert(std::forward<R>(r),
                       static_cast<typename Field::value_type>(v.value));
     }
 
     template <typename N, stdx::range R>
     constexpr static auto set_default(R &&r) -> void {
-        check<field_t<N>, std::remove_cvref_t<R>>();
+        check<N, std::remove_cvref_t<R>>();
         field_t<N>::insert_default(std::forward<R>(r));
     }
 
     template <typename N, stdx::range R> constexpr static auto get(R &&r) {
-        check<field_t<N>, std::remove_cvref_t<R>>();
+        check<N, std::remove_cvref_t<R>>();
         return field_t<N>::extract(std::forward<R>(r));
     }
 

test/msg/fail/CMakeLists.txt

@@ -13,8 +13,12 @@ add_compile_fail_test(message_cmp_view.cpp LIBRARIES warnings cib_msg)
 add_compile_fail_test(message_const_field_write.cpp LIBRARIES warnings cib_msg)
 add_compile_fail_test(message_dangling_view.cpp LIBRARIES warnings cib_msg)
 add_compile_fail_test(message_dup_fieldnames.cpp LIBRARIES warnings cib_msg)
+add_compile_fail_test(message_get_nonexistent_field.cpp LIBRARIES warnings
+                      cib_msg)
 add_compile_fail_test(message_incompatible_matcher.cpp LIBRARIES warnings
                       cib_msg)
+add_compile_fail_test(message_set_nonexistent_field.cpp LIBRARIES warnings
+                      cib_msg)
 add_compile_fail_test(message_uninitialized_field.cpp LIBRARIES warnings
                       cib_msg)
 add_compile_fail_test(view_upsize.cpp LIBRARIES warnings cib_msg)

test/msg/fail/message_get_nonexistent_field.cpp

@@ -0,0 +1,17 @@
+#include <msg/field.hpp>
+#include <msg/message.hpp>
+
+// EXPECT: Field does not belong to this message
+namespace {
+using namespace msg;
+
+using test_field1 =
+    field<"test_field", std::uint32_t>::located<at{0_dw, 31_msb, 24_lsb}>;
+
+using msg_defn = message<"test_msg", test_field1>;
+} // namespace
+
+auto main() -> int {
+    owning<msg_defn> m{};
+    [[maybe_unused]] auto f = m.get("no"_field);
+}

test/msg/fail/message_set_nonexistent_field.cpp

@@ -0,0 +1,17 @@
+#include <msg/field.hpp>
+#include <msg/message.hpp>
+
+// EXPECT: Field does not belong to this message
+namespace {
+using namespace msg;
+
+using test_field1 =
+    field<"test_field", std::uint32_t>::located<at{0_dw, 31_msb, 24_lsb}>;
+
+using msg_defn = message<"test_msg", test_field1>;
+} // namespace
+
+auto main() -> int {
+    owning<msg_defn> m{};
+    m.set("no"_field = 1);
+}