Found the following significant warnings:
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:14229:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:14230:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:14232:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:16393:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:16394:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:16396:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:20872:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:20873:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/../../simdjson.h:20875:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/RcppSimdJson/deserialize/Type_Doctor.hpp:43:65: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:14229:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:14230:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:14232:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:16393:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:16394:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:16396:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:20872:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:20873:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
  ../inst/include/simdjson.h:20875:32: warning: template-id not allowed for constructor in C++20 [-Wtemplate-id-cdtor]
See ‘/data/gannet/ripley/R/packages/tests-devel/RcppSimdJson.Rcheck/00install.out’ for details.
* used C++ compiler: ‘g++-14 (GCC) 14.1.0’