test: add test for multiple translation unit

tests/CMakeLists.txt

@@ -98,3 +98,8 @@ foreach(TEST_NAME ${TEST_NAMES})
         )
     endif()
 endforeach(TEST_NAME)
+
+# this test is to check it compiles. it will not run
+add_executable(test_multiple_translation_unit
+               test_multiple_translation_unit_1.cpp
+               test_multiple_translation_unit_2.cpp)

tests/test_multiple_translation_unit_1.cpp

@@ -0,0 +1,11 @@
+#include <toml.hpp>
+
+int read_a(const toml::table&);
+
+int main()
+{
+    const std::string content("a = 0");
+    std::istringstream iss(content);
+    const auto data = toml::parse(iss, "test_multiple_translation_unit.toml");
+    return read_a(data);
+}

tests/test_multiple_translation_unit_2.cpp

@@ -0,0 +1,6 @@
+#include <toml.hpp>
+
+int read_a(const toml::table& t)
+{
+    return toml::get<int>(t.at("a"));
+}