#include "libutil/config.hh" #include "primops.hh" using namespace nix; struct MySettings : Config { Setting<bool> settingSet{this, false, "setting-set", "Whether the plugin-defined setting was set"}; }; MySettings mySettings; static GlobalConfig::Register rs(&mySettings); static void prim_anotherNull(EvalState& state, const Pos& pos, Value** args, Value& v) { if (mySettings.settingSet) mkNull(v); else mkBool(v, false); } static RegisterPrimOp rp("anotherNull", 0, prim_anotherNull);