Compilare: user.cpp: In instantiation of ‘void Convolution<type>::computeConvolution(std::vector<std::complex<_Tp> >&, std::vector<std::complex<_Tp> >&, std::vector<std::complex<_Tp> >&, int, int) [with type = double]’: user.cpp:118:76: required from here user.cpp:77:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pol1.size() < (1 << size)) pol1.resize(1 << size); user.cpp:78:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pol2.size() < (1 << size)) pol2.resize(1 << size); user.cpp:79:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pol3.size() < (1 << size)) pol3.resize(1 << size);