[BUG] unsigned int is too small for bytes defined at GadgetUtils/GadgetUtils.h:643

[HelloGithubC]

Hello,

I have run a N-body by your code with npar=800^3 and obtained a Segmentation fault. I found the problem with gdb that the bytes you defined to contain pos of particles to write is defiened as unsigned int, which is too small even though I use npar=800^3(800^3*3*sizeof(float) > 2^32-1).

Attach the code in GadgetUtils/GadgetUtils.h:
unsigned int bytes = ntowrite * NDIM * sizeof(float);
buffer = std::vector(bytes);

            // If particles have family then sort POS of them by family in the buffer
            if constexpr (FML::PARTICLE::has_get_pos<T>()) {
                bytes = ntowrite * NDIM * sizeof(float);
                buffer.resize(bytes);
                float_buffer = reinterpret_cast<float *>(buffer.data());
                size_t count = 0;
                for (int curfamily = 0; curfamily < 6; curfamily++) {
                    if (npart_family[curfamily] > 0) {
                        for (size_t j = 0; j < ntowrite; j++) {
                            auto * pos = FML::PARTICLE::GetPos(part[j]);
                            if constexpr (FML::PARTICLE::has_get_family<T>()) {
                                auto family = FML::PARTICLE::GetFamily(part[j]);
                                if (family == curfamily) {
                                    for (int idim = 0; idim < NDIM; idim++)
                                        float_buffer[NDIM * count + idim] = float(pos[idim]) * pos_norm;
                                    count++;
                                }
                            } else {
                                for (int idim = 0; idim < NDIM; idim++)
                                    float_buffer[NDIM * count + idim] = float(pos[idim]) * pos_norm;
                                count++;
                            }
                        }
                    }
                }
                assert(count == ntowrite);
                write_section(fp, buffer, bytes);
            }