#ifdef USE_TBB
    #include <tbb/parallel_for.h>
#endif //USE_TBB
 
#include <iostream>
 
namespace serial {
    template<typename Count, typename UnaryFunc>
    void numeric_for(Count first, Count last, UnaryFunc f) {
        while(first!=last) {
            f(first);
            ++first;
        }
    }
}
 
namespace compat {
    template<typename Count, typename UnaryFunc>
    void numeric_for(Count first, Count last, UnaryFunc f) {
    #ifdef USE_TBB
        tbb::parallel_for(first, last, f);
    #else
        serial::numeric_for(first, last, f);
    #endif
    }
}
 
int main() {
    compat::numeric_for(
        1,
        30,
        [](int i){ std::cout << i << '\t'; }
    );
}

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