\u72ec\u5360\u6240\u6709\u6743，\u540c\u4e00\u65f6\u95f4\u53ea\u80fd\u6709\u4e00\u4e2aunique_ptr\u6307\u5411\u8fd9\u5757\u5806\u5185\u5b58，\u7981\u6b62\u62f7\u8d1d，\u53ea\u5141\u8bb8\u79fb\u52a8\u3002<\/p>\n
\u00a0 \u4e0d\u80fd\u62f7\u8d1d：unqiue_ptr<int> p2 = p1；\u7f16\u8bd1\u62a5\u9519；<\/p>\n
\u00a0 \u53ef\u4ee5\u79fb\u52a8：unique_ptr<int> p2 = move(p1)；\u79fb\u52a8\u540ep1\u53d8\u6210\u7a7a，p2\u63a5\u7ba1\u8d44\u6e90；<\/p>\n
\u00a0 \u751f\u547d\u5468\u671f：\u51fa\u4f5c\u7528\u57df，\u81ea\u52a8\u8c03\u7528delete\u91ca\u653e\u5185\u5b58；<\/p>\n
\u793a\u4f8b\u4ee3\u7801：<\/p>\n
#include <iostream>
\n#include <memory>
\nusing namespace std;<\/p>\n
int main()
\n{
\n \/\/ \u521b\u5efaunique_ptr，\u7ba1\u7406\u5806\u4e0aint
\n unique_ptr<int> p1(new int(100));
\n cout << *p1 << endl;<\/p>\n
\/\/ unique_ptr<int> p2 = p1; \/\/ \u274c \u7f16\u8bd1\u62a5\u9519！\u7981\u6b62\u62f7\u8d1d，\u72ec\u5360<\/p>\n
unique_ptr<int> p2 = move(p1); \/\/ \u2705 \u79fb\u52a8\u6240\u6709\u6743
\n cout << *p2 << endl;
\n \/\/ p1 \u73b0\u5728\u662f\u7a7a\u6307\u9488，\u4e0d\u80fd\u518d\u4f7f\u7528*p1<\/p>\n
return 0;
\n} \/\/ \u51fa\u4f5c\u7528\u57df，p2\u9500\u6bc1，\u81ea\u52a8\u91ca\u653e\u5806\u5185\u5b58，\u4e0d\u7528\u624b\u52a8delete<\/p>\n
\u8981\u70b9：<\/p>\n
1.\u5e95\u5c42：\u6790\u6784\u7684\u65f6\u5019\u76f4\u63a5\u91ca\u653e\u5185\u5b58，\u6ca1\u6709\u5f15\u7528\u8ba1\u6570，\u5f00\u9500\u5f88\u5c0f；<\/p>\n
2.\u9002\u7528\u573a\u666f：\u8d44\u6e90\u53ea\u9700\u8981\u4e00\u4e2a\u7ba1\u7406\u8005（\u7edd\u5927\u591a\u6570\u573a\u666f\u4f18\u5148\u7528unique_ptr）；<\/p>\n
3.C++14\u63a8\u8350\u5199\u6cd5：auto p = make_unique<int>(100)；<\/p>\n<\/p>\n
\u5171\u4eab\u6240\u6709\u6743，\u7ef4\u62a4\u5f15\u7528\u8ba1\u6570；\u6bcf\u591a\u4e00\u4e2ashared_ptr\u6307\u5411\u540c\u4e00\u5757\u5185\u5b58，\u8ba1\u6570+1；\u5bf9\u8c61\u6790\u6784\u8ba1\u6570-1；\u5f15\u7528\u8ba1\u6570\u51cf\u52300，\u91ca\u653e\u5806\u5185\u5b58\u3002<\/p>\n
\u00a0 \u5f15\u7528\u8ba1\u6570：\u5355\u72ec\u5b58\u653e\u5728\u5806\u4e0a，\u4e0d\u662f\u5b58\u5728\u5bf9\u8c61\u5185\u90e8；<\/p>\n
\u00a0 \u62f7\u8d1d\u5141\u8bb8：\u62f7\u8d1d\u65f6\u5f15\u7528\u8ba1\u6570+1；<\/p>\n
\u00a0 \u79fb\u52a8：\u539f\u6307\u9488\u7f6e\u7a7a，\u8ba1\u6570\u4e0d\u53d8；<\/p>\n
\u793a\u4f8b\u4ee3\u7801：<\/p>\n
#include <iostream>
\n#include <memory>
\nusing namespace std;<\/p>\n
int main()
\n{
\n shared_ptr<int> p1 = make_shared<int>(200); \/\/ \u8ba1\u6570=1
\n cout << p1.use_count() << endl; \/\/ use_count\u67e5\u770b\u5f15\u7528\u8ba1\u6570<\/p>\n
shared_ptr<int> p2 = p1; \/\/ \u2705 \u5141\u8bb8\u62f7\u8d1d，\u5171\u4eab\u8d44\u6e90，\u8ba1\u6570=2
\n cout << p2.use_count() << endl;<\/p>\n
p1.reset(); \/\/ p1\u653e\u5f03\u7ba1\u7406，\u8ba1\u6570=1
\n cout << p2.use_count() << endl;<\/p>\n
return 0;
\n} \/\/ \u51fd\u6570\u7ed3\u675fp2\u6790\u6784，\u8ba1\u6570\u53d8\u62100，\u91ca\u653e\u5185\u5b58<\/p>\n
\u4e24\u4e2a\u5bf9\u8c61A，B，A\u91cc\u9762\u5b58shared_ptr<B>，B\u91cc\u9762\u5b58shared_ptr A\u6301\u6709B，B\u6301\u6709A\u3002\u4e24\u4e2a\u5bf9\u8c61\u6790\u6784\u7684\u65f6\u5019，\u5f15\u7528\u8ba1\u6570\u90fd\u51cf\u52301，\u6c38\u8fdc\u4e0d\u4e3a0，\u5185\u5b58\u6c38\u8fdc\u4e0d\u91ca\u653e\u3002<\/p>\n
struct B;
\nstruct A{
\n shared_ptr<B> b_ptr;
\n ~A(){cout << "A\u6790\u6784"<<endl;}
\n};
\nstruct B{
\n shared_ptr<A> a_ptr;
\n ~B(){cout << "B\u6790\u6784"<<endl;}
\n};<\/p>\n
int main()
\n{
\n shared_ptr<A> a = make_shared<A>();
\n shared_ptr<B> b = make_shared<B>();
\n a->b_ptr = b;
\n b->a_ptr = a;
\n \/\/ \u51famain，a\u3001b\u6790\u6784，\u4f46\u662f\u5185\u90e8\u4e92\u76f8\u6301\u6709，\u5f15\u7528\u8ba1\u6570=1
\n \/\/ A\u3001B\u7684\u6790\u6784\u51fd\u6570**\u4e0d\u4f1a\u6267\u884c，\u5185\u5b58\u6cc4\u6f0f！**
\n return 0;
\n}<\/p>\n
\u8fd0\u884c\u7ed3\u679c：\u4e0d\u4f1a\u6253\u5370A\u6790\u6784，B\u6790\u6784，\u5185\u5b58\u6cc4\u6f0f；<\/p>\n
\u89e3\u51b3\u65b9\u6848：\u628a\u5176\u4e2d\u4e00\u4e2ashared_ptr\u6539\u4e3aweak_ptr；<\/p>\n<\/p>\n
\u4e0d\u589e\u52a0shared_ptr\u7684\u5f15\u7528\u8ba1\u6570，\u4e0d\u62e5\u6709\u8d44\u6e90，\u53ea\u662f\u201c\u65c1\u89c2\u201dshared_ptr\u7ba1\u7406\u7684\u5bf9\u8c61<\/p>\n
\u00a0 weak_ptr\u4e0d\u80fd\u76f4\u63a5\u89e3\u5f15\u7528\u8bbf\u95ee\u5bf9\u8c61，\u5fc5\u987b\u8c03\u7528.lock()，\u8fd4\u56de\u4e00\u4e2a\u4e34\u65f6shared_ptr；<\/p>\n
\u00a0 \u00a0 lock()\u5e95\u5c42\u662f\u5982\u4f55\u64cd\u4f5c\u7684<\/p>\n
\u62ff\u5230 weak_ptr \u4fdd\u5b58\u7684\u63a7\u5236\u5757\u5730\u5740（weak_ptr \u5185\u90e8\u53ea\u5b58\u63a7\u5236\u5757\u6307\u9488 + \u5bf9\u8c61\u6307\u9488，\u4e0d\u6301\u6709\u5bf9\u8c61）<\/p>\n<\/li>\n
\u539f\u5b50\u64cd\u4f5c\u8bfb\u53d6 use_count，\u5224\u65ad use_count > 0<\/p>\n
\u5982\u679c use_count == 0：\u5bf9\u8c61\u5df2\u7ecf\u88ab\u91ca\u653e \u2192 \u76f4\u63a5\u8fd4\u56de\u7a7a\u7684shared_ptr<\/p>\n<\/li>\n
\u5982\u679c use_count > 0：\u5c1d\u8bd5\u539f\u5b50\u5730\u628a use_count +=1（\u539f\u5b50！\u9632\u6b62\u591a\u7ebf\u7a0b\u5e76\u53d1\u91ca\u653e）<\/p>\n<\/li>\n<\/ul>\n<\/li>\n
\u6784\u9020\u4e00\u4e2a\u65b0\u7684 shared_ptr，\u628a\u5bf9\u8c61\u6307\u9488\u3001\u63a7\u5236\u5757\u6307\u9488\u4ea4\u7ed9\u8fd9\u4e2a\u65b0 shared_ptr \u8fd4\u56de<\/p>\n<\/li>\n
\u6574\u4e2a\u8fc7\u7a0b\u662f\u539f\u5b50\u7684，\u9632\u6b62\u591a\u7ebf\u7a0b\u4e0b \u201c\u5224\u65ad\u5b8c\u8fd8\u6ca1\u52a0\u8ba1\u6570，\u5bf9\u8c61\u5c31\u88ab\u522b\u7684\u7ebf\u7a0b\u91ca\u653e\u201d<\/p>\n<\/li>\n
\u00a0\u53ef\u4ee5\u7528.expired()\u5224\u65ad\u8d44\u6e90\u662f\u5426\u5df2\u7ecf\u88ab\u91ca\u653e；<\/p>\n
\u00a0 \u4e13\u95e8\u89e3\u51b3shared_ptr\u5faa\u73af\u5f15\u7528\u95ee\u9898；<\/p>\n
\u4fee\u590d\u4e0a\u9762\u5faa\u73af\u5f15\u7528\u4ee3\u7801（\u628aA\u5185\u90e8\u7684shared_ptr<B>\u6539\u4e3aweak_ptr<B>）<\/p>\n
#include <iostream>
\n#include <memory>
\nusing namespace std;<\/p>\n
struct B;
\nstruct A{
\n weak_ptr<B> b_ptr; \/\/ \u5f31\u6307\u9488！\u4e0d\u589e\u52a0\u5f15\u7528\u8ba1\u6570
\n ~A(){cout << "A\u6790\u6784"<<endl;}
\n};
\nstruct B{
\n shared_ptr<A> a_ptr;
\n ~B(){cout << "B\u6790\u6784"<<endl;}
\n};<\/p>\n
int main()
\n{
\n shared_ptr<A> a = make_shared<A>();
\n shared_ptr<B> b = make_shared<B>();
\n a->b_ptr = b; \/\/ weak_ptr\u8d4b\u503c，b\u7684\u5f15\u7528\u8ba1\u6570\u4e0d\u4f1a+1
\n b->a_ptr = a;<\/p>\n
return 0;
\n}
\n\/\/ \u8f93\u51fa：A\u6790\u6784 B\u6790\u6784，\u5185\u5b58\u6b63\u5e38\u91ca\u653e！<\/p>\n
\u5f53main\u51fd\u6570\u7ed3\u675f：<\/p>\n
1.b\u6790\u6784，B\u5185\u90e8a_ptr\u8ba1\u6570\u51cf1，a\u7684\u5f15\u7528\u8ba1\u6570\u53d8\u62100->A\u5bf9\u8c61\u91ca\u653e；<\/p>\n
2.A\u91ca\u653e\u540e，weak_ptr\u81ea\u52a8\u5931\u6548，\u6ca1\u6709\u6307\u9488\u518d\u6301\u6709B，B\u7684\u5f15\u7528\u8ba1\u6570\u53d8\u62100->B\u91ca\u653e\u3002<\/p>\n
\u4f7f\u7528weak_ptr\u8bbf\u95ee\u5bf9\u8c61\u793a\u4f8b：<\/p>\n
shared_ptr<int> s = make_shared<int>(666);
\nweak_ptr<int> w = s;
\n\/\/ cout << *w; \/\/ \u274c weak_ptr\u4e0d\u80fd\u76f4\u63a5\u89e3\u5f15\u7528
\nshared_ptr<int> tmp = w.lock(); \/\/ \u62ff\u5230\u4e34\u65f6shared_ptr
\nif(tmp != nullptr)
\n{
\n cout << *tmp << endl;
\n}<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e00 unique_ptr\u72ec\u5360\u667a\u80fd\u6307\u9488\u72ec\u5360\u6240\u6709\u6743，\u540c\u4e00\u65f6\u95f4\u53ea\u80fd\u6709\u4e00\u4e2aunique_ptr\u6307\u5411\u8fd9\u5757\u5806\u5185\u5b58，\u7981\u6b62\u62f7\u8d1d，\u53ea\u5141\u8bb8\u79fb\u52a8\u3002\u4e0d\u80fd\u62f7\u8d1d：unqiue_ptr p2 p1；\u7f16\u8bd1\u62a5\u9519；\u53ef\u4ee5\u79fb\u52a8：unique_ptr p2 move(p1)；\u79fb\u52a8\u540ep1\u53d8\u6210\u7a7a，p2\u63a5\u7ba1\u8d44\u6e90；\u751f\u547d\u5468\u671f：\u51fa\u4f5c\u7528\u57df，\u81ea<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[55,190],"topic":[],"class_list":["post-115331","post","type-post","status-publish","format-standard","hentry","category-server","tag-c","tag-190"],"yoast_head":"\n