class File 
{
// unsigned int modified : 1; // 浣嶅煙 (bit-field)
};
浣嶅煙鏍囪瘑絎﹀悗闈㈣窡鏈変竴涓啋鍙鳳紝鐒跺悗鏄竴涓父閲忚〃杈懼紡鎸囧畾浣嶆暟銆備緥濡俶odified 鏄竴涓彧鏈変竴浣嶆瀯鎴愮殑浣嶅煙銆?br> 鍦ㄧ被浣撲腑鐩擱偦瀹氫箟鐨勪綅鍩燂紝濡傛灉鍙兘鐨勮瘽錛屽畠浠細(xì)琚斁鍦ㄥ悓涓涓暣鏁扮殑榪炵畫浣嶄腑錛屽茍浠ユ鎻愪緵絀洪棿鍘嬬緝銆備緥濡傦紝鍦ㄤ笅鍒楀０鏄庝腑5 涓綅鍩熻瀛樺偍鍦ㄥ崟涓猽nsigned int 涓紝瀹冮鍏堜笌浣嶅煙mode 鐩稿叧鑱斻?/p>
typedef unsigned int Bit;class File {public:Bit mode: 2;Bit modified: 1;Bit prot_owner: 3;Bit prot_group: 3;Bit prot_world: 3;// };
浣嶅煙鍦ㄥ唴瀛樹腑鐨勪綅緗槸浠庝綆浣嶅悜楂樹綅鏀劇疆鐨勶紝姣斿mode鍦˙it鐨勬渶浣庝袱浣嶏紙浜岃繘鍒舵暟0b0000000000000011涓袱涓?鐨勪綅緗級(jí)銆?/span>
瀵逛簬浣嶅煙鐨勮闂柟寮忎笌鍏朵粬綾繪暟鎹垚鍛樼浉鍚屻備緥濡傦紝綾葷殑縐佹湁浣嶅煙鍙兘鍦ㄧ被鐨勬垚鍛樺嚱鏁板拰鍙嬪厓涓璁塊棶錛?/p>
void File::write(){modified = 1;// }void File::close(){if ( modified )// 鍐呭浠庣暐}
涓嬮潰鐨勪緥瀛愯鏄庝簡鎬庢牱浣跨敤澶т簬1 浣嶇殑浣嶅煙enum { READ = 01, WRITE = 02 }; // 鏂囦歡妯″紡int main() {File myFile;myFile.mode |= READ;if ( myFile.mode & READ )cout << "myFile.mode is set to READ\n";}
閫氬父鎯呭喌涓嬫垜浠細(xì)瀹氫箟涓緇刬nline 鎴愬憳鍑芥暟錛屾潵嫻嬭瘯姣忎釜浣嶅煙鎴愬憳鐨勫箋備緥濡傦紝綾籉ile鍙互瀹氫箟鎴愬憳isRead()鍜宨sWrite()inline int File::isRead() { return mode & READ; }inline int File::isWrite() { return mode & WRITE; }if ( myFile.isRead() ) /**//* */
鏈変簡榪欎簺鎴愬憳鍑芥暟錛岀幇鍦ㄤ綅鍩熷彲浠ヨ澹版槑涓虹被File 鐨勭鏈夋垚鍛樸?br> 鐢變簬鍙栧湴鍧鎿嶄綔絎?amp; 涓嶈兘琚簲鐢ㄥ湪浣嶅煙涓婏紝鎵浠ヤ篃娌℃湁鑳芥寚鍚戠被鐨勪綅鍩熺殑鎸囬拡銆備綅鍩熶篃涓嶈兘鏄被鐨勯潤鎬佹垚鍛樸?/span>
C++鏍囧噯搴撴彁渚涗簡涓涓猙itset 綾繪ā鏉匡紝瀹冨彲浠ヨ緟鍔╂搷綰典綅鐨勯泦鍚堛傚湪鍙兘鐨勬儏鍐典笅搴斿敖鍙兘浣跨敤瀹冩潵鍙栦唬浣嶅煙銆?/p>
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