Compilare: user.cpp: In function ‘void do_test(std::ifstream&, std::ofstream&)’: user.cpp:81:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < rez.size(); ++i){ ^ user.cpp: In instantiation of ‘void fft(T, int) [with int arg_mult = 1; T = std::complex<double>*]’: user.cpp:53:21: required from here user.cpp:38:12: warning: unused variable ‘n2’ [-Wunused-variable] const int n2 = n/2; ^ user.cpp: In instantiation of ‘void fft(T, int) [with int arg_mult = -1; T = std::complex<double>*]’: user.cpp:59:21: required from here user.cpp:38:12: warning: unused variable ‘n2’ [-Wunused-variable]