How to add string condition matching judgment to the. stg template? If I add this syntax, it will report an error; Without this condition, the template can be generated normally. I am not very familiar with ST syntax. Can you help me solve this problem

[Eternity1987]

$if(struct.scopedname.first()=="shm_msgs")$`
// Skip NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT for shm_msgs namespace
$else$
#ifndef SWIG
#include <nlohmann/json.hpp>
NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT($struct.name$,$\n$$struct.members:{m |$m.name$}; separator=", "$)
#endif
$endif$

or

$if(someflag)$
#include <nlohmann/json.hpp>
NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT($struct.name$,$\n$$struct.members:{m |$m.name$}; separator=", "$)
#endif