????vector?????????????????????????????????????????????????????????????
????vector?????????塣
????vector???????????vector??????????????????Ч?????????????????????
?????????????????????
??????????????????ж????κι?????????????????????????????????????????????е???????????????????????
????vector?±???????????
for(vector<int>::size_type ix = 0; ix != ivec.size(); ++ix)
ivec[ix] =0;
????(1)
??????????!= ??????????????<????????
????size()?????н????????vector???????????????????????size()????????????inline??????
???????????????????????±?????????????“??????“????????????ν??”?????????“???????°??????
??????????
????????????????????????????????????????????(???????????????????????????Щ?????????????????????????Щ????????????????????)
vector<int>::iterator iter;
vector<int>::iterator iter=ivec.begin(); //vector?????????ivec[0]
vector<int>::iterator iter=ivec.end();    //???vector?????????????????vectro????begin??end?????????????
vector<int>::const_iterator   iter;
//???????????????????????????????*iter = 0??????
const vector<int>::iterator iter = ivec.begin(); //????????????????????++iter??????
????????????????????????????????????????????????
for(vector<int>::iterator iter = ivec.begin(); iter != ivec.end(); ++iter)
*iter = 0;
????(2)
????(1)??(2)???   ??2???????vector??????????????????begin??end??????????????