ar*</code>) values from attributes together with <code>const_string&lt;N&gt;</code> and in <code>constexpr</code> context possible. That feature is exposed by the <code><a class="el" href="refl_8hpp.html#a2cb939da062920a29a38dff73aaf0968" title="Converts a compile-time available const char* value to a const_string&lt;N&gt;.">REFL_MAKE_CONST_STRING(CString)</a></code> macro. Important: <code>CString</code> must be a <a href="https://en.cppreference.com/w/cpp/language/constant_expression#Core_constant_express