Compilare: main.cpp: In function 'int main()': main.cpp:21:37: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { fread(buff, buff_size,1, stdin); ^ main.cpp: In function 'void read(int&)': main.cpp:11:111: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] while(buff[pos] < '0' || buff[pos] > '9') if(++pos == buff_size) fread(buff, buff_size,1, stdin), pos = 0; ^ main.cpp:16:73: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] if(++pos == buff_size) fread(buff, 1, buff_size, stdin), pos = 0; ^