include(FetchContent) set(JSON_MultipleHeaders OFF) FetchContent_Declare( json GIT_REPOSITORY https://github.com/ArthurSonzogni/nlohmann_json_cmake_fetchcontent.git GIT_TAG 67e6070f9d9a44b4dec79ebe6b591f39d2285593 GIT_PROGRESS TRUE ) message("json") FetchContent_MakeAvailable(json) # Show json project add_library(json ${json_SOURCE_DIR}/single_include/nlohmann/json.hpp) set_property(TARGET json PROPERTY CXX_STANDARD 23) set_target_properties(json PROPERTIES LINKER_LANGUAGE CXX)