????1?????????
????"??"??"????"??????????????????????????????????????????????????C++???????????????????豸???????????????????????????????????????????????豸?????????????????????????????????????????????????"??"??
?????????????????????????C++????????I/O??????е????????????????????????????????????????????????????????????????????????
?????????????????????豸?????????????????????????????????????????????????????????????????洢??????????????
?????????????????????????
??????????????λ????????????????????????????????ASCII???????????????????????????????????????????????????????????????????????????????????????
????2??IO??
????C++??IO???????STL??????????STL?ж?????????????????????й????????

????????????????/????????????istream(????)??ostream?????????iostream?????????????????istream??ostream????ios?м?У?iostream????????istream??otream????cin??STL?ж?λ??????????????istream????cout??cerr??clog???????????????ostream????????cout?????????????????????????????????cerr?????????????????????????????????????clog????????????????????????????cerr??clog?????????????cerr???????????????????????????й????????clog????????????????????????????????????endl?????????????
????????????????????ifstream???????????ofstream????????????fstream???????????/???????????ifstream???istream?м?е???ofstream???ostream?м?е???fstream???iostream??е???
??????????????????????istringstream?????????????ostringstream??????????????stringstream?????????????/???????????istringstream???istream?м?е???ostringstream???ostream?м?е???stringstream???iostream??е???
????3??<<??>>?????? 3.1 <<???÷?
??????istream?????????ж????ж??????????>>???????鷲?ó???????????????????????????
????istream& operator>> (istream& is?? char& c);
????istream& operator>> (istream& is?? signed char& c);
????istream& operator>> (istream& is?? unsigned char& c);
????istream& operator>> (istream& is?? char* s);
????istream& operator>> (istream& is?? signed char* s);
????istream& operator>> (istream& is?? unsigned char* s);
?????????????????????????????????????????????????????????????????????????????????????????
???????????cin>>variable????????????????x??????????????????????????????????variable??????????????βΣ???????????????ж?????????????variable??????cin?????????????????????????????????????????
??????????????????????????е??????????????????????????????????????????????????cin??????????????????У???????????????????????????????????????????cin??????????????????????????????????????????
??????cin>>str_ptr?????е?str_ptr?????????????????????????????ж???????????????????????str_ptr??????洢????У???str_ptr?????????????????д???????洢?????????????????????????????????????????????????????????????????????????????????????????????????????????????????е???????????
????3.2 >>???÷?
??????ostream????????ж????ж??????????<<???????鷲?ó???????????????????????????
????istream& operator>> (bool& val);
????istream& operator>> (short& val);
????istream& operator>> (unsigned short& val);
????istream& operator>> (int& val);
????istream& operator>> (unsigned int& val);
????istream& operator>> (long& val);
????istream& operator>> (unsigned long& val);
????istream& operator>> (long long& val);
????istream& operator>> (unsigned long long& val);
????istream& operator>> (float& val);
????istream& operator>> (double& val);
????istream& operator>> (long double& val);
????istream& operator>> (void*& val);
????????????istream?????????????????????????????????????????????????????????void* ?????????????κ??????????????????????????????????????????????????洢????б???????????????????
???????????????????????????????????????????????????????????????統(tǒng)???????cout?????????????????????????????????????????????
???????????cout<<variable??????????????x??????????????????????????????????variable?????????????????βΣ???????к????壬??variable????????βε??????????????????????????????λ??????????????????cout????????????ò?????????????????????????
????4??IO?????? 4.1 ?????????
????IO???????п???????????Щ???????????????????????????????????????????ó?????????????Χ??
????IO???????Щ????????????????????????????????????????
??????????????????????????????????strm::iostate??????strm??????????????????iostream??fstream??????磬?????????????IO??????
????iostream::iostate strm_state=iostream::goodbit;
????IO??漲????4??iostate?????contexpr???????????λ??????Щ????????????????IO????????????λ?????????????????????????????λ??
????1??strm::badbit???????????????????????????????粻???????д???????????￡????badbit????λ???????????????
????2??strm::failbit??????????IO??????????
????3??strm::eofbit???????????????????????
??????????????????failbit????λ???????????????????????????????????????????????????????????????á???????????????λ???eofbit??failbit??????λ??
????4??strm::goodbit?????????δ????????????????????
????goodbit????0???????δ???????????badbit??failbit??eofbit???????λ??????????????????????
?????????????????麯?????????Щ???λ??????????s??????????????
????s.eof() // ????s??eofbit??λ??????true
????s.fail() // ????s??failbit??badbit??λ??????true
????s.bad() // ????s??badbit????λ??????true
????s.good() // ????s??????Ч????????true
?????????????????????ж????????????Ч???????????????????????磺while(cin>>variable){cout<<variable}????????ж???????while((cin>>variable).good()){cout<<variable}??