add Chapter18

Chapter18/cib/libs/log/module.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <log/env.hpp>
+
+#include <stdx/ct_string.hpp>
+
+#include <utility>
+
+namespace logging {
+[[maybe_unused]] constexpr inline struct get_module_t {
+    template <typename T>
+        requires true // more constrained
+    CONSTEVAL auto operator()(T &&t) const noexcept(
+        noexcept(std::forward<T>(t).query(std::declval<get_module_t>())))
+        -> decltype(std::forward<T>(t).query(*this)) {
+        return std::forward<T>(t).query(*this);
+    }
+
+    CONSTEVAL auto operator()(auto &&) const {
+        using namespace stdx::literals;
+        return "default"_ctst;
+    }
+} get_module;
+} // namespace logging
+
+// NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
+#define CIB_LOG_MODULE(S) CIB_LOG_ENV(logging::get_module, S)