Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:20:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,Nmax,fin); ^ user.cpp: In function ‘int main()’: user.cpp:30:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buffer, 1, Nmax, fin); ^