{"id":45,"date":"2015-07-05T10:34:25","date_gmt":"2015-07-05T02:34:25","guid":{"rendered":"http:\/\/zsaber.com\/blog\/?p=45"},"modified":"2019-08-26T15:29:18","modified_gmt":"2019-08-26T07:29:18","slug":"stl-%e4%b8%ad-erase-%e7%9a%84%e9%82%a3%e4%ba%9b%e5%9d%91","status":"publish","type":"post","link":"http:\/\/zsaber.com\/blog\/?p=45","title":{"rendered":"STL \u4e2d erase \u7684\u90a3\u4e9b\u5751"},"content":{"rendered":"

STL \u4e2d erase \u7684\u5751\u4f30\u8ba1\u4e0d\u5c11\u4eba\u90fd\u8e29\u8fc7, \u81ea\u8ba4\u4e3a\u5df2\u7ecf\u514d\u75ab\u4e86, \u7ed3\u679c\u6700\u8fd1\u53c8\u8e29\u4e86\u6b21\u5751, \u4e8e\u662f\u6012\u53d1\u6b64\u6587<\/p>\n

\u5927\u591a\u4eba\u80af\u5b9a\u90fd\u662f\u4ece\u6700\u7b80\u5355\u7684\u5751\u8e29\u8fc7\u6765\u7684:<\/p>\n

some_container a;\nfor(iterator it = a.begin(); it != a.end(); ++it)\n{\n    if(shouldDelete(it))\n    {\n        a.erase(it);\n    }\n}<\/code><\/pre>\n
\u8fd9\u4e2a\u5c5e\u4e8e\u521d\u7ea7\u7684\u5751, \u5bf9\u4e8e\u6240\u6709 STL \u5bb9\u5668\u90fd\u4f1a\u51fa\u95ee\u9898, \u5927\u4f53\u539f\u56e0\u5c31\u662f erase \u4e4b\u540e it \u5df2\u7ecf\u662f\u65e0\u6548\u7684\u4e86<\/p>\n
\u4e8e\u662f, \u5927\u591a\u6570\u4eba\u7ed9\u51fa\u4e86\u5982\u4e0b\u4e24\u79cd\u65b9\u6848<\/p>\n
\u65b9\u6848\u4e00:<\/p>\n
it = a.erase(it);<\/code><\/pre>\n
\u65b9\u6848\u4e8c:<\/p>\n
a.erase(it++);<\/code><\/pre>\n
\u7136\u540e\u7686\u5927\u6b22\u559c\u7684\u8ba4\u4e3a\u641e\u5b9a\u4e00\u5207\u4e86<\/p>\n
\u4f60\u4ee5\u4e3a\u5751\u90fd\u586b\u6ee1\u4e86? \u56fe\u6837\u56fe\u68ee\u7834<\/p>\n
\u9996\u5148, map::erase \u5728\u6807\u51c6\u4e2d\u53ef\u662f\u4e0d\u8fd4\u56de iterator \u7684:<\/p>\n
void erase(iterator position);<\/code><\/pre>\n
\u7136\u800c, \u4e07\u6076\u7684\u5fae\u8f6f\u5e76\u4e0d\u9075\u5faa\u6807\u51c6, \u5bf9\u4e8e map::erase \u4e5f\u8fd4\u56de\u4e86 iterator, \u4e8e\u662f, \u8ddf\u7740\u5fae\u8f6f\u8d70\u7684\u7334\u5b50\u4eec\u5f00\u5f00\u5fc3\u5fc3\u7684\u89e3\u51b3\u4e0b\u4e00\u4e2a BUG \u53bb\u4e86<\/p>\n
\u9075\u5faa\u6807\u51c6\u7684\u7334\u5b50\u4eec\u95ee\u5019\u4e86\u4e0b STL \u7684\u7956\u5b97, \u7136\u540e\u82b1\u5927\u529b\u6c14\u628a\u6240\u6709 erase \u90fd\u6539\u6210\u4e86\u65b9\u6848\u4e8c erase(it++) \u7684\u7248\u672c, \u8ba4\u4e3a\u5929\u4e0b\u7ec8\u4e8e\u592a\u5e73\u4e86<\/p>\n
… \u5417? \u56fe\u6837\u56fe\u68ee\u7834, \u6765\u7528\u4f60\u7684\u7f16\u8bd1\u5668\u8bd5\u8bd5\u5982\u4e0b\u4ee3\u7801\u5427:<\/p>\n
deque a;\na.push_back(something);\niterator it = a.begin();\na.erase(it++);\nassert(it == a.end());<\/code><\/pre>\n
\u5982\u4f55? boom \u4e86\u5427? \u8fd9\u5c31\u662f\u8fd9\u6b21\u6211\u8e29\u5230\u7684\u5751, erase(it++) \u5bf9\u4e8e map \u4e4b\u6d41\u5de5\u4f5c\u7684\u5f88\u597d, \u4f46\u662f\u5bf9\u4e8e deque \u5374\u4e0d\u662f\u4f60\u60f3\u8c61\u7684\u90a3\u6837<\/p>\n
\u867d\u7136\u5148\u6267\u884c\u4e86 it++ \u4f7f it \u53d8\u6210\u4e86 end(), \u53ef\u662f erase \u4e4b\u540e\u8fd8\u662f\u5bfc\u81f4 it \u5931\u6548\u4e86<\/p>\n
\u7528\u6bd4\u8f83\u5bb9\u6613\u61c2\u7684\u65b9\u5f0f\u6765\u89e3\u91ca\u5c31\u662f:<\/p>\n