锘??xml version="1.0" encoding="utf-8" standalone="yes"?>久久福利片,久久久这里只有精品加勒比,成人国内精品久久久久影院http://m.shnenglu.com/lwkaoyan/zh-cnFri, 04 Jul 2025 21:18:46 GMTFri, 04 Jul 2025 21:18:46 GMT60new/delete 鎿嶄綔絎?/title><link>http://m.shnenglu.com/lwkaoyan/archive/2008/03/21/45013.html</link><dc:creator>鏄熺綏媯嬪竷</dc:creator><author>鏄熺綏媯嬪竷</author><pubDate>Fri, 21 Mar 2008 01:29:00 GMT</pubDate><guid>http://m.shnenglu.com/lwkaoyan/archive/2008/03/21/45013.html</guid><wfw:comment>http://m.shnenglu.com/lwkaoyan/comments/45013.html</wfw:comment><comments>http://m.shnenglu.com/lwkaoyan/archive/2008/03/21/45013.html#Feedback</comments><slash:comments>1</slash:comments><wfw:commentRss>http://m.shnenglu.com/lwkaoyan/comments/commentRss/45013.html</wfw:commentRss><trackback:ping>http://m.shnenglu.com/lwkaoyan/services/trackbacks/45013.html</trackback:ping><description><![CDATA[<p>[TC++PL] new/delete 鎿嶄綔絎?br> <br> <br>Cpp Operators of new and delete<br>1. 鍔ㄦ佸唴瀛樺垎閰嶄笌閲婃斁(new and delete)<br>涓鑸鏉ワ紝涓涓璞$殑鐢熷懡鏈熸槸鐢卞畠琚垱寤烘椂鎵澶勭殑鍖哄煙鍐沖畾鐨勩備緥濡傦紝鍦ㄤ竴瀵箋}綾誨畾涔夌殑涓涓璞★紝鍦ㄧ寮榪欎釜鐢眥}鎵鐣屽畾鐨勫尯鍩熸椂錛岃瀵硅薄灝變細琚攢姣侊紝鍦ㄨ繖涓尯鍩熶箣澶栬繖涓璞℃槸涓嶅瓨鍦ㄧ殑錛岀▼搴忕殑鍏朵粬閮ㄥ垎涓嶈兘鍐嶅紩鐢ㄨ繖涓璞′簡銆?/p> <p> </p> <p>濡傛灉甯屾湜鍦ㄧ寮浜嗗垱寤鴻繖涓璞℃椂鎵澶勭殑鍖哄煙鍚庯紝榪樺笇鏈涜繖涓璞″瓨鍦ㄥ茍鑳界戶緇紩鐢ㄥ畠錛屽氨蹇呴』鐢╪ew鎿嶄綔絎﹀湪鑷敱瀛樺偍絀洪棿鏉ュ垎閰嶄竴涓璞°傝繖涓繃紼嬩篃鍙仛鍔ㄦ佸唴瀛樺垎閰嶏紝涔熷彨鍫嗗璞°備換浣曠敱new鎿嶄綔絎﹀垎閰嶇殑瀵硅薄閮藉簲璇ョ敤delete鎿嶄綔絎︽墜鍔ㄥ湴閿姣佹帀銆侰++鏍囧噯騫舵病鏈夊畾涔変換浣曞艦寮忕殑“鍨冨溇鏀墮泦”鏈哄埗銆俤elete鎿嶄綔絎﹀彧鑳界敤浜庣敱new榪斿洖鐨勬寚閽堬紝鎴栬呮槸闆躲傚綋delete鐨勫弬鏁版槸0鏃訛紝涓嶄細浜х敓浠諱綍鏁堟灉錛屼篃灝辨槸璇磋繖涓猟elete鎿嶄綔絎﹀搴旂殑鍑芥暟鏍規(guī)湰灝變笉浼氳鎵ц銆?/p> <p> </p> <p>new錛坉elete錛夋棦鍙互鍒嗛厤錛堥噴鏀撅級鍗曚釜鐨勫璞★紙褰撶劧涔熷寘鎷唴寤虹被鍨嬶級錛屼篃鍙互鍒嗛厤錛堥噴鏀撅級瀵硅薄鏁扮粍銆備笅闈㈡槸鍏跺嚱鏁板師鍨嬶細<br>#include <new></p> <p>void* operator new(size_t); // 鍙傛暟鏄崟涓璞$殑澶у皬</p> <p>void* operator new[](size_t); // 鍙傛暟鏄璞℃暟緇勭殑鎬葷殑澶у皬</p> <p>void delete(void*);</p> <p>void delete[](void*);</p> <p>C++鏍囧噯涓茍娌℃湁瑕佹眰new鎿嶄綔絎﹀鍒嗛厤鍑烘潵鐨勭┖闂磋繘琛屽垵濮嬪寲銆備笅闈㈡槸浣跨敤new鍒嗛厤涓涓瓧絎︽暟緇勭殑渚嬪瓙錛?br>char* save_string(const char* p)</p> <p>{<br>char* s = new char[strlen(p)+1];</p> <p>// ...</p> <p>return s;</p> <p>}</p> <p> </p> <p>char* p = save_string(argv[1]);</p> <p>// ...</p> <p>delete[] p;</p> <p> </p> <p><br>class X { /* ... */ }</p> <p>X* p = new[10] X; </p> <p>X* p2 = new X[10];</p> <p>vector<int>* pv = new vector<int>(5);</p> <p>鍦╪ew鍒嗛厤鍑鴻凍澶熺殑絀洪棿鍚庯紝緙栬瘧鍣ㄤ細绱ф帴鐫璋冪敤X鐨勭己鐪佹瀯閫犲嚱鏁板絀洪棿榪涜鍒濆鍖栥傛敞鎰忥紝涓婅堪涓ょ褰㈠紡閮芥槸鍙互鐨勶紝鏃犺X鏄唴寤虹被鍨嬭繕鏄嚜瀹氫箟鐢ㄦ埛綾誨瀷銆傚浜庣被鏉ヨ錛岃繕鍙互浣跨敤綾葷殑鏋勯犲嚱鏁板艦寮忥紝濡備笂闈㈠垱寤簐ector綾誨瀷瀵硅薄鐨勪緥瀛愩傛澶栵紝涓涓敤闈炴暟緇勫艦寮忕殑new鎿嶄綔絎﹀垱寤虹殑瀵硅薄錛屼笉鑳界敤鏁扮粍褰㈠紡鐨刣elete鎿嶄綔絎︽潵閿姣併?/p> <p>2. 鎻愪緵鑷繁鐨勫唴瀛樼鐞嗭細閲嶈澆new/delete鎿嶄綔絎?br>鎴戜滑鍙互涓簄ew/delete瀹氫箟鑷繁鐨勫唴瀛樼鐞嗘柟寮忥紝浣嗘槸鏇挎崲鍏ㄥ眬鐨刵ew/delete鎿嶄綔絎︾殑瀹炵幇鏄笉澶熷ソ鐨勶紝鍘熷洜寰堟槑鏄撅細鏈変簺浜哄彲鑳介渶瑕佺己鐪佺殑new/delete鎿嶄綔鐨勪竴浜涙柟闈紝鑰屽彟涓浜涗漢鍒欏彲鑳藉畬鍏ㄤ嬌鐢ㄥ彟澶栦竴縐嶇増鏈殑瀹炵幇銆傛墍浠ユ渶濂界殑鍔炴硶鏄負鏌愪釜鐗瑰畾鐨勭被鎻愪緵瀹冭嚜宸辯殑鍐呭瓨綆$悊鏂瑰紡銆?/p> <p> </p> <p>涓涓被鐨刼perator new()鍜宱perator delete()鎴愬憳鍑芥暟錛岄殣寮忓湴鎴愪負闈欐佹垚鍛樺嚱鏁般傚洜姝ゅ畠浠病鏈塼his鎸囬拡錛屼篃涓嶈兘淇敼瀵硅薄錛堝緢濂界悊瑙o紝褰撹皟鐢╪ew鐨勬椂鍊欏璞¤繕娌℃湁鐪熸鍒涘緩鍛紝褰撶劧涓嶈兘淇敼瀵硅薄浜嗭紒錛夈傚綋鐒跺湪閲嶈澆瀹氫箟鐨勬椂鍊欙紝鍘熷瀷榪樻槸瑕佷笌鍓嶉潰鎻愬埌鐨勪竴鑷淬傜湅涓嬮潰榪欎釜渚嬪瓙錛?/p> <p>void* Employee::operator new(size_t s)</p> <p>{<br>// 鍒嗛厤s瀛楄妭鐨勫唴瀛樼┖闂達紝騫惰繑鍥炶繖涓┖闂寸殑鍦板潃</p> <p>锝?/p> <p> </p> <p>void Employee::operator delete(void* p, size_t s)</p> <p>{<br>// 鍋囧畾鎸囬拡p鏄寚鍚戠敱Employee::operator new()鍒嗛厤鐨勫ぇ灝忎負s瀛楄妭鐨勫唴瀛樼┖闂淬?/p> <p>// 閲婃斁榪欏潡絀洪棿浠ヤ緵緋葷粺鍦ㄤ互鍚庨噸鐢ㄣ?/p> <p>}<br>浠諱綍涓涓猳perator new()鐨勬搷浣滅瀹氫箟錛岄兘浠ヤ竴涓昂瀵稿間綔涓虹涓涓弬鏁幫紝涓斿緟鍒嗛厤瀵硅薄鐨勫ぇ灝忛殣寮忕粰瀹氾紝鍏跺煎氨浣滀負new鎿嶄綔絎﹀嚱鏁扮殑絎竴涓弬鏁板箋?/p> <p> </p> <p><br>鍦ㄨ繖閲屽垎閰嶇┖闂寸殑鍏蜂綋瀹炵幇鍙互鏄縐嶅鏍風(fēng)殑錛屽彲浠ョ洿鎺ヤ嬌鐢╩alloc/free錛堢己鐪佺殑鍏ㄥ眬new/delete澶ч儴鍒嗛兘鏄敤鐨勮繖縐嶏級錛屽彲浠ュ湪鎸囧畾鐨勫唴瀛樺潡涓垎閰嶇┖闂達紙涓嬭妭灝嗚璇﹁堪錛夛紝涔熷彲鑳借繕鏈夊叾浠栫殑鏇村ソ鐨勬洿閫傚悎浣犵殑搴旂敤鐨勬柟寮忋?/p> <p> </p> <p>閭d箞濡備綍閲嶈澆鏁扮粍褰㈠紡鐨刵ew[]/delete[]鎿嶄綔絎﹀憿錛熶笌鏅氬艦寮忎竴鏍鳳紝鍙笉榪嘾elete[]鐨勫弬鏁板艦寮忕◢鏈変笉鍚岋紝濡備笅鎵紺猴細<br>class Employee {</p> <p>public:<br>void* operator new[](size_t);</p> <p>void operator delete[](void*); // 鍗曞弬鏁板艦寮忥紝灝戜簡涓涓猻ize_t鍙傛暟</p> <p>void operator delete[](void*,size_t); //涓や釜鍙傛暟褰㈠紡涔熸槸鍙互鐨勶紝浣嗘棤蹇呰</p> <p>// ...</p> <p>};</p> <p> </p> <p>鍦ㄧ紪璇戝櫒鐨勫唴閮ㄥ疄鐜頒腑錛屼紶鍏ew/delete[]鐨勫昂瀵稿煎彲鑳芥槸鏁扮粍鐨勫ぇ灝弒鍔犱笂涓涓猟elta銆傝繖涓猟elta閲忔槸緙栬瘧鍣ㄧ殑鍐呴儴瀹炵幇鎵瀹氫箟鐨勬煇縐嶉澶栧紑閿銆備負浠涔坉elete鎿嶄綔絎︿笉闇瑕佺浜屼釜灝哄鍙傛暟鍛紵鍥犱負榪欎釜鏁扮粍鐨勫ぇ灝弒浠ュ強delta閲忛兘鐢辯郴緇?#8220;璁頒綇”浜嗐備絾鏄痙elete[]鐨勪袱涓弬鏁板艦寮忕殑鍘熷瀷涔熸槸鍙互澹版槑鐨勶紝鍦ㄨ皟鐢ㄧ殑鏃跺欎細鎶妔*sizeof(SomeClass)+delta浣滀負絎簩涓弬鏁板間紶鍏ャ俤elta閲忔槸涓庣紪璇戝櫒瀹炵幇鐩稿叧鐨勶紝鍥犳瀵逛簬鐢ㄦ埛紼嬪簭鍛樻潵璇存槸涓嶅繀瑕佺煡閬撶殑銆傛晠鑰岃繖閲屽彧鎻愪緵鍗曞弬鏁扮増鏈氨鍙互浜嗐傦紙榪欏掓槸鎻愪緵浜嗕竴縐嶆煡鐪嬭繖涓猟elta閲忕殑鏂規(guī)硶銆傛牴鎹疄闄呮祴璇曪紝GCC 4.1閲囩敤浜?涓瓧鑺傜殑delta閲忋傦級</p> <p> </p> <p><br>鍒拌繖閲屽簲璇ユ敞鎰忓埌錛屽綋鎴戜滑璋冪敤operator delete()鐨勬椂鍊欙紝鍙粰鍑轟簡鎸囬拡錛屽茍娌℃湁緇欏嚭瀵硅薄澶у皬鐨勫弬鏁般傞偅涔堢紪璇戝櫒鏄庝箞鐭ラ亾搴旇緇檕perator delete()鎻愪緵姝g‘鐨勫昂瀵稿肩殑鍛紵濡傛灉delete鍙傛暟綾誨瀷灝辨槸璇ュ璞$殑紜垏鍨嬪埆錛岄偅涔堣繖鏄竴涓畝鍗曠殑浜嬫儏錛屼絾鏄簨鎯呭茍涓嶆槸鎬繪槸榪欐牱銆傜湅涓嬮潰鐨勪緥瀛愶細</p> <p>class Manager : public Employee {</p> <p>int level;</p> <p>// ...</p> <p>};<br>void f()</p> <p>{<br>Employee* p = new Manager; // 楹葷儲錛氱‘鍒囧瀷鍒涪澶變簡錛?/p> <p>delete p;</p> <p>}<br>榪欎釜鏃跺欑紪璇戝櫒涓嶈兘寰楀埌姝g‘鐨勫璞$殑灝哄銆傝繖灝遍渶瑕佺敤鎴風(fēng)殑甯姪浜嗭細鍙渶瑕佸皢鍩虹被鐨勬瀽鏋勫嚱鏁板0鏄庣О涓鴻櫄鍑芥暟鍗沖彲銆?/p> <p> </p> <p>3. 鍦ㄦ寚瀹氫綅緗畨鏀懼璞?Placement of Objects)<br>new鎿嶄綔絎︾殑緙虹渷鏂瑰紡鏄湪鑷敱鍐呭瓨絀洪棿涓垱寤哄璞°傚鏋滃笇鏈涘湪鎸囧畾鐨勫湴鏂瑰垎閰嶅璞★紝灝卞簲璇ヤ嬌鐢ㄨ繖閲屼粙緇嶇殑鏂規(guī)硶銆傜湅涓嬮潰鐨勪緥瀛愶細<br>class X {</p> <p>public:<br>X(int);<br>//...<br>};<br>褰撻渶瑕佹妸瀵硅薄鏀劇疆鍒版寚瀹氬湴鏂圭殑鏃跺欙紝鍙渶瑕佷負鍒嗛厤鍑芥暟鎻愪緵涓涓澶栫殑鍙傛暟錛堟棦鎸囧畾鐨勬煇澶勫唴瀛樼殑鍦板潃錛夛紝鐒跺悗鍦ㄤ嬌鐢╪ew鐨勬椂鍊欐彁渚涜繖鏍風(fēng)殑涓涓澶栧弬鏁板嵆鍙傜湅涓嬮潰鐨勪緥瀛愶細<br>void* operator new(size_t, void* p) { return p; } // 鏄劇ず瀹夋斁鎿嶄綔絎?/p> <p>void* buf = reinterpret_cast<void*>(0xF00F); // 鏌愪釜閲嶈鐨勫湴鍧</p> <p>X* p2 = new(buf) X; // 鍦╞uf鍦板潃澶勫垱寤轟竴涓猉瀵硅薄錛?/p> <p>// 瀹為檯璋冪敤鍑芥暟operator new(sizeof(X),buf)</p> <p> </p> <p><br>4. 鍐呭瓨鍒嗛厤澶辮觸涓巒ew_handler<br>濡傛灉new鎿嶄綔絎︿笉鑳藉垎閰嶅嚭鍐呭瓨錛屼細鍙戠敓浠涔堝憿錛熼粯璁ゆ儏鍐典笅錛岃繖涓垎閰嶅櫒浼氭姏鍑轟竴涓猙ad_alloc寮傚父瀵硅薄銆傜湅涓嬮潰鐨勪緥瀛愶細<br>void f()</p> <p>{<br>try{<br>for(;;) new char [10000];</p> <p>}<br>catch(bad_alloc) {</p> <p>cerr << "Memory exhausted!\n";</p> <p>}<br>}<br>[鐤戦棶錛氭瀯閫犱竴涓紓甯稿璞′篃闇瑕佸唴瀛樼┖闂達紝鏃㈢劧宸茬粡鍐呭瓨鑰楀敖浜嗭紝閭h繖涓唴瀛樺張浠庡摢閲屾潵鍛紵]<br>鍙互鑷畾涔夊唴瀛樿楀敖鏃剁殑澶勭悊鏂規(guī)硶(new_handler)銆傚綋new鎿嶄綔澶辮觸鏃訛紝棣栧厛浼氳皟鐢ㄤ竴涓敱set_new_handler()鎸囧畾鐨勫嚱鏁般傛垜浠彲浠ヨ嚜瀹氫箟榪欎釜鍑芥暟錛岀劧鍚庣敤set_new_handler()鏉ョ櫥璁般傛渶鍚庡綋new鎿嶄綔澶辮觸鏃跺彲浠ヨ皟鐢ㄩ傚綋鐨勮嚜瀹氫箟澶勭悊榪囩▼銆傜湅涓嬮潰鐨勪緥瀛愶細<br>#include <new> // set_new_handler()鍘熷瀷鍦ㄦ澶存枃浠朵腑</p> <p>void out_of_store()</p> <p>{<br>cerr << "operator new failed: out of store\n";</p> <p>throw bad_alloc();</p> <p>}</p> <p> </p> <p>set_new_handler(out_of_store);<br>for(;;) new char[10000];</p> <p>cout << "done\n";</p> <p> </p> <p><br>涓婅堪渚嬪瓙涓帶鍒舵祦涓嶄細鍒拌揪鏈鍚庝竴鍙ヨ緭鍑猴紝涔熷氨鏄姘歌繙涓嶄細杈撳嚭done銆傝屾槸浼氳緭鍑猴細<br>operator new failed: out of store</p> <p>鑷畾涔夌殑new_handler鍑芥暟鐨勫師鍨嬪涓嬶細<br>typedef void (*new_handler)(); </p> <p><br>5. 鏍囧噯澶存枃浠?lt;new>涓殑鍘熷瀷<br>涓嬮潰鏄爣鍑嗗ご鏂囦歡涓殑鍚勭鍘熷瀷澹版槑錛?br>class bad_alloc : public exception { /* ... */ }</p> <p> </p> <p><br>struct nothrow_t { };</p> <p>extern struct nothrow_t nothrow; // 鍐呭瓨鍒嗛厤鍣ㄥ皢涓嶄細鎶涘嚭寮傚父</p> <p> </p> <p><br>typedef void (*new_handler)();</p> <p>new_handler set_new_handler(new_handler new_p) throw();</p> <p> </p> <p><br>錛?錛夋櫘閫氱殑鍐呭瓨鍒嗛厤錛屽け璐ユ椂鎶涘嚭bad_alloc寮傚父<br>// 鍗曚釜瀵硅薄鐨勫垎閰嶄笌閲婃斁</p> <p>void* operator new(size_t) throw(bad_alloc);</p> <p>void operator delete(void*) throw();</p> <p>// 瀵硅薄鏁扮粍鍒嗛厤涓庨噴鏀?/p> <p>void* operator new[](size_t) throw(bad_alloc);</p> <p>void operator delete[](void*) throw();</p> <p> </p> <p><br>錛?錛変笌C鏂瑰紡鍏煎鐨勫唴瀛樺垎閰嶏紝澶辮觸鏃惰繑鍥?錛屼笉鎶涘嚭寮傚父<br>// 鍗曚釜瀵硅薄鍒嗛厤涓庨噴鏀?/p> <p>void* operator new(size_t, const nothrow_t&) throw();</p> <p>void operator delete(void*, const nothrow_t&) throw();</p> <p>// 瀵硅薄鏁扮粍鍒嗛厤涓庨噴鏀?/p> <p>void* operator new[](size_t, const nothrow_t&) throw();</p> <p>void operator delete[](void*, const nothrow_t&) throw();</p> <p> </p> <p><br>錛?錛変粠鎸囧畾絀洪棿涓垎閰嶅唴瀛?br>// 鍒嗛厤宸叉湁絀洪棿緇欏崟涓璞′嬌鐢?/p> <p>void* operator new(size_t, void* p) throw() { return p; } </p> <p>void operator delete(void* p, void*) throw() { } //浠涔堥兘涓嶅仛錛?/p> <p>// 鍒嗛厤宸叉湁絀洪棿緇欏璞℃暟緇勪嬌鐢?/p> <p>void* operator new[](size_t, void* p) throw() {return p;}</p> <p>void operator delete[](void* p, void*) throw() { } //浠涔堜篃涓嶅仛錛?/p> <p> </p> <p><br>鍦ㄤ笂榪板師鍨嬩腑錛屾姏鍑虹┖寮傚父鐨勫嚱鏁伴兘娌℃湁鍔炴硶閫氳繃鎶涘嚭std::bad_alloc鍙戝嚭鍐呭瓨鑰楀敖鐨勪俊鍙鳳紱瀹冧滑鍦ㄥ唴瀛樺垎閰嶅け璐ユ椂榪斿洖0銆?/p> <p> </p> <p>涓婅堪鍘熷瀷鐨勪嬌鐢ㄦ柟娉曪細<br>class X {</p> <p>public: </p> <p>X(){};<br>X(int n){};</p> <p>// ...</p> <p>};<br>錛?錛夊彲浠ユ姏鍑哄紓甯哥殑new/delete鎿嶄綔絎︺?br>鍘熷瀷鐨勭涓涓弬鏁幫紝鍗沖璞★紙鎴栧璞℃暟緇勶級鐨勫ぇ灝忥紝鍥犳鍦ㄤ嬌鐢ㄦ椂濡備笅鎵紺猴細<br>X* p = new X;</p> <p>X* p1 = new X(5);</p> <p>X* pa = new X[10]; </p> <p>鍒嗛厤瀵硅薄鏁扮粍鏃惰娉ㄦ剰錛氬彧鑳界敤榪欑褰㈠紡錛屼笉鑳界敤甯﹀弬鏁扮殑褰㈠紡錛屼緥濡備笅闈㈢殑鏂瑰紡鏄敊璇殑錛?br>X* pa2 = new[20] X(5);</p> <p>浣犳兂鍒嗛厤涓涓猉鏁扮粍錛屾瘡涓暟緇勫厓绱犻兘鐢?榪涜鍒濆鍖栵紝榪欐槸涓嶈兘鍋氬埌鐨勩?/p> <p> </p> <p>錛?錛変笉鎶涘嚭寮傚父鑰岃繑鍥?鐨刵ew/delete鎿嶄綔絎?br>鍘熷瀷鐨勭浜屼釜鍙傛暟瑕佹眰涓涓猲othrow_t鐨勫紩鐢紝鍥犳蹇呴』浠?lt;new>涓畾涔夌殑nothrow鍏ㄥ眬瀵硅薄浣滀負new/delete鐨勫弬鏁幫紝濡備笅鎵紺猴細</p> <p>void f()</p> <p>{<br>int* p = new int[10000]; // 鍙兘浼氭姏鍑篵ad_alloc寮傚父</p> <p> </p> <p><br>if(int* q = new(nothrow) int[100000]; {</p> <p>// 鍐呭瓨鍒嗛厤鎴愬姛</p> <p>delete(nothrow)[]q;<br>}<br>else {</p> <p>// 鍐呭瓨鍒嗛厤澶辮觸</p> <p>}<br>}</p> <p> </p> <p>6. new涓庡紓甯?br>濡傛灉鍦ㄤ嬌鐢╪ew鏋勯犲璞℃椂錛屾瀯閫犲嚱鏁版姏鍑轟簡寮傚父錛岀粨鏋滀細鎬庢牱錛熺敱new鍒嗛厤鐨勫唴瀛橀噴鏀句簡鍚楋紵鍦ㄩ氬父鎯呭喌涓嬬瓟妗堟槸鑲畾鐨勶紱浣嗗鏋滄槸鍦ㄦ寚瀹氫綅緗笂鍒嗛厤瀵硅薄絀洪棿錛岄偅涔堢瓟妗堝氨涓嶆槸榪欎箞綆鍗曚簡銆傚鏋滆繖涓唴瀛樺潡鏄敱鏌愪釜綾葷殑new鍑芥暟鍒嗛厤鐨勶紝閭d箞灝變細璋冪敤鍏剁浉搴旂殑delete鍑芥暟錛堝鏋滄湁鐨勮瘽錛夛紝鍚﹀垯涓嶄細鏈夐噴鏀懼唴瀛樼殑鍔ㄤ綔鍙戠敓銆傝繖縐嶇瓥鐣ュ緢濂藉湴澶勭悊浜嗘爣鍑嗗簱涓殑浣跨敤鎸囧畾鍐呭瓨鐨刵ew鎿嶄綔絎︼紝浠ュ強鎻愪緵浜嗘垚瀵圭殑鍒嗛厤涓庨噴鏀懼嚱鏁扮殑浠諱綍鎯呭艦銆?br>鐪嬩笅闈㈣繖涓緥瀛愶細<br>void f(Arena& a, X* buffer)</p> <p>{<br>X* p1 = new X; </p> <p>X* p2 = new X[10];</p> <p>X* p3 = new(buffer[10]) X;</p> <p>X* p4 = new(buffer[11]) X[10];</p> <p>X* p5 = new(a) X;</p> <p>X* p6 = new(a) X[10];</p> <p>}<br>鍒嗘瀽錛歱1鍜宲2灝嗚兘姝g‘閲婃斁鍏跺垎閰嶇殑鍐呭瓨錛屼笉浼氶犳垚鍐呭瓨娉勬紡錛岃繖灞炰簬涓縐嶆甯告儏鍐點傚悗闈㈢殑鍥涚鎯呭喌鍒欐瘮杈冨鏉傘傚璞濡傛灉鏄噰鐢ㄦ櫘閫氭柟寮忓垎閰嶇殑鍐呭瓨錛岄偅涔堝皢鑳藉姝g‘閲婃斁鍏舵嫢鏈夌殑鍐呭瓨銆?/p> <p> </p> <p>7. malloc/free娌$敤浜嗗悧錛?br>new鑳藉瀹屽叏鏇夸唬malloc鍚楋紵緇濆ぇ閮ㄥ垎鎯呭喌涓嬶紝絳旀閮芥槸鑲畾鐨勩備絾鏄湁涓縐嶆儏鍐靛垯闈炵敤malloc涓嶅彲浜嗐傛牴鎹畁ew鐨勫畾涔夛紝鍏剁涓涓弬鏁版槸寰呭垎閰嶅璞$殑澶у皬錛屼絾鍦ㄤ嬌鐢ㄦ椂涓嶉渶瑕佹槑紜湴緇欏嚭榪欎釜鍊箋傝繖涓兼槸鐢辯紪璇戝櫒鏆椾腑鏇夸綘瀹屾垚鐨勩傚樿嫢鍦ㄦ煇縐嶆儏鍐典笅錛岄渶瑕佸湪鍒嗛厤涓涓璞$殑鍚屾椂榪樿鍒嗛厤鍑轟竴浜涢澶栫殑絀洪棿鐢ㄦ潵綆$悊鏌愪簺鐩稿叧鐨勪俊鎭傝繖涓澶栫┖闂翠笌瀵硅薄鐨勭┖闂磋姹傝繛緇傝繖涓椂鍊檔ew灝卞府涓嶄笂浜嗐傚繀欏葷敤malloc鎶婂璞″拰棰濆絀洪棿鐨勬誨ぇ灝忎綔涓簃alloc鐨勫弬鏁般傚湪鍒嗛厤鍑烘潵浜嗗悗錛屽彲鑳介渶瑕佽皟鐢╪ew鐨勬斁緗艦寮忕殑璋冪敤鍦ㄨ鍧楀唴瀛樹笂鏋勯犲璞°?br>8. 鍨冨溇鏀墮泦<br>褰撴垜浠負鑷繁鐨勭被鎻愪緵浜嗚嚜宸辯殑鍐呭瓨綆$悊鏂規(guī)硶鏃訛紝鏈夊彲鑳戒細鍑虹幇鍐呭瓨鍒嗛厤澶辮觸鐨勬儏鍐點傚洜姝ゆ垜浠彲鑳戒細閫氳繃set_new_handler()鎻愪緵涓涓洿鐏靛閥鐨勫唴瀛橀噴鏀句笌閲嶇敤鏈哄埗銆傝繖灝變負瀹炵幇鍨冨溇鏀墮泦鎻愪緵浜嗕竴涓疄鐜版濊礬銆傚瀮鍦炬敹闆嗘満鍒剁殑鍩烘湰鎬濇兂鏄紝褰撲竴涓璞′笉鍐嶈寮曠敤鏃訛紝瀹冪殑鍐呭瓨灝卞彲浠ュ畨鍏ㄥ湴琚柊鐨勫璞℃墍浣跨敤銆?br>褰撴瘮杈冨瀮鍦炬敹闆嗘満鍒朵笌鎵嬪伐綆$悊鏂瑰紡鐨勪唬浠鋒椂錛屼粠涓涓嬪嚑涓柟闈㈣繘琛屾瘮杈冿細<br>榪愯鏃墮棿錛屽唴瀛樼殑浣跨敤錛屽彲闈犳э紝縐繪鎬э紝緙栫▼鐨勮垂鐢紝鍨冨溇鏀墮泦鍣ㄧ殑璐圭敤錛屾ц兘鐨勯鏈熴?/p> <p> </p> <p>鍨冨溇鏀墮泦鍣ㄥ繀欏昏澶勭悊鍑犱釜閲嶈鐨勯棶棰橈細<br>錛?錛夋寚閽堢殑浼<br>閫氬父鑻ヤ互闈炴寚閽堢殑褰㈠紡鏉ュ瓨鍌ㄤ竴涓寚閽堬紝鍒欐妸榪欎釜鎸囬拡鍙仛“浼鐨勬寚閽?#8221;銆傜湅涓嬮潰榪欎釜渚嬪瓙錛?br>void f()</p> <p>{<br>int* p = new int;</p> <p>long i1 = reinterpret_cast<long>(p) & 0xFFFF0000;</p> <p>long i2 = reinterpret_cast<long>(p) & 0x0000FFFF;</p> <p>p = 0;</p> <p>// 榪欓噷灝變笉瀛樺湪鎸囧悜閭d釜鏁村瀷鏁扮殑鎸囬拡浜嗭紒</p> <p>p = reinterpret_cast<int*>(i1|i2);</p> <p>// 鐜板湪榪欎釜鏁村瀷鏁板張琚紩鐢ㄤ簡錛?/p> <p>}<br>涓婁緥涓師鏈敱p鎸佹湁鐨勬寚閽堣浼鎴愪袱涓暣鍨嬫暟i1鍜宨2銆傚瀮鍦炬敹闆嗗櫒蹇呴』鍏蟲敞榪欑浼鐨勬寚閽堛?br>鎸囬拡浼榪樻湁鍙﹀涓縐嶅艦寮忥紝鍗沖悓鏃舵湁鎸囬拡鍜岄潪鎸囬拡鎴愬憳鐨剈nion緇撴瀯錛屼篃浼氱粰鍨冨溇鏀墮泦鍣ㄥ甫鏉ョ壒孌婄殑闂銆傜湅涓嬮潰鐨勪緥瀛愶細<br>union U {</p> <p>int* p;</p> <p>int i;</p> <p>};</p> <p> </p> <p>void f(U u, U u2, U u3)</p> <p>{<br>u.p = new int;</p> <p>u2.i = 99999;</p> <p>u.i = 8;</p> <p>// ...</p> <p>}<br>閫氬父榪欐槸涓嶅彲鑳界煡閬搖nion涓寘鍚殑鏄寚閽堣繕鏄暣鏁般?/p> <p> </p> <p>錛?錛塪elete鍑芥暟<br>閫氬父鑻ヤ嬌鐢ㄤ簡鑷姩鍨冨溇鏀墮泦錛岄偅涔坉elete鍜宒elete[]鍑芥暟鏄笉鍐嶉渶瑕佷簡鐨勩備絾鏄痙elete鍜宒elete[]鍑芥暟闄や簡閲婃斁鍐呭瓨鐨勫姛鑳藉錛岃繕浼氳皟鐢ㄦ瀽鏋勫嚱鏁般傚洜姝ゅ湪榪欑鎯呭喌涓嬶紝涓嬪垪璋冪敤<br>delete p;</p> <p>灝卞彧璋冪敤鏋愭瀯鍑芥暟錛岃屽唴瀛樼殑澶嶇敤鍒欏悜鍚庢帹榪燂紝鐩村埌鍐呭瓨鍧楄鏀墮泦銆備竴嬈″洖鏀跺涓璞★紝鏈夊姪浜庡噺灝戠鐗囥?/p> <p> </p> <p>錛?錛夋瀽鏋勫嚱鏁?br>褰撳瀮鍦炬敹闆嗗櫒鍑嗗鍥炴敹瀵硅薄鏃訛紝鏈変袱縐嶅姙娉曞彲閫夛細<br>[1] 涓鴻繖涓璞¤皟鐢ㄦ瀽鏋勫嚱鏁幫紙濡傛灉鏈夌殑璇濓級錛?/p> <p>[2] 灝嗚繖涓璞″綋浣滃師濮嬪唴瀛橈紙鍗充笉璋冪敤鏋愭瀯鍑芥暟錛夈?/p> <p>涓鑸瀮鍦炬敹闆嗗櫒浼氶夋嫨絎簩涓柟娉曘傝繖縐嶆柟娉昰c灝辨垚涓烘ā鎷熶竴縐嶆棤闄愬唴瀛樼殑鏈哄埗銆?br>涔熸湁鍙兘璁捐涓縐峠c錛屽畠鑳借皟鐢ㄥ悜瀹冩敞鍐屼簡鐨勫璞$殑鏋愭瀯鍑芥暟銆傝繖縐嶈璁$殑涓涓噸瑕佹柟闈㈡槸闃叉鏋愭瀯鍑芥暟閲嶅鍒犻櫎涓涓箣鍓嶅凡緇忓垹闄ょ殑瀵硅薄銆?/p> <p> </p> <p>錛?錛夊唴瀛樼殑紕庣墖<br>澶勭悊鍐呭瓨紕庣墖鐨勯棶棰樹笂錛屾湁涓ょ涓昏鐨凣C綾誨瀷錛氭嫹璐濆瀷鍜屼繚瀹堝瀷銆傛嫹璐濆瀷GC閫氳繃縐誨姩瀵硅薄浣垮緱紕庣墖絀洪棿绱у噾錛涜屼繚瀹堝瀷鍒欓氳繃鍒嗛厤鏂瑰紡鐨勬敼鍠勬潵鍑忓皯紕庣墖銆侰++鐨勮鐐圭湅鏉ワ紝鏇村懼悜浜庝繚瀹堝瀷鐨勩傚洜涓虹Щ鍔ㄥ璞″皢瀵艱嚧澶ч噺鐨勬寚閽堝拰寮曠敤絳夊け鏁堬紝鎵浠ユ嫹璐濆瀷GC鍦–++涓嚑涔庢槸涓嶅彲鑳藉疄鐜扮殑銆傛澶栦繚瀹堝瀷GC涔熷彲浠ヨC++鐨勪唬鐮佹涓嶤浠g爜孌靛叡瀛樸?<br> <br></p> <img src ="http://m.shnenglu.com/lwkaoyan/aggbug/45013.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://m.shnenglu.com/lwkaoyan/" target="_blank">鏄熺綏媯嬪竷</a> 2008-03-21 09:29 <a href="http://m.shnenglu.com/lwkaoyan/archive/2008/03/21/45013.html#Feedback" target="_blank" style="text-decoration:none;">鍙戣〃璇勮</a></div>]]></description></item></channel></rss> <footer> <div class="friendship-link"> <p>感谢您访问我们的网站,您可能还对以下资源感兴趣:</p> <a href="http://m.shnenglu.com/" title="精品视频久久久久">精品视频久久久久</a> <div class="friend-links"> </div> 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