Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:25:45: 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,buffersize,stdin); l=0; ^ user.cpp:32:45: 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,buffersize,stdin); l=0; ^ user.cpp: In function ‘int main()’: user.cpp:125:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rev.in","r",stdin); ^ user.cpp:126:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rev.out","w",stdout); ^ user.cpp:127:33: 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,buffersize,stdin); l=0; ^