namespace boost {
template <typename T, typename C>
T lexical_cast(const C&) {
    return T();
}

}

namespace std {
    template <typename T>
    class basic_string {};
    using string = basic_string<char>;
}


int g();
long long f(int p);
using namespace boost;

template <typename T>
void string_as_T() {
    boost::lexical_cast<T>(42);
}

int main() {
string_as_T<std::string>();
}