// 1
Project::Init("project_root_directory", "project_build_directory");

// 2
Storage::Add<Target>("identifier", ...);
auto & t = Storage::Ref<Target>("identifier");
const auto & t = Storage::ConstRef<Target>("identifier");

// 3
Reg::Init(...);
Reg::Build(...)
Reg::Dep(target, dependency);
Reg::Callback(...);

// 4
Args::Init(...);
Args::AddToolchain(...);