Pkg-config¶
If you are using bare Makefiles, you can use pkg-config to generate the include flags that point to where the library is installed:
pkg-config nlohmann_json --cflags
A pkg-config file is installed by CMake (when the JSON_Install option is enabled, which is the default for a top-level build) as well as by several package managers.
Users of the Meson build system will also be able to use a system-wide library, which will be found by pkg-config:
json = dependency('nlohmann_json', required: true)