{"id":94706,"date":"2026-08-15T01:48:47","date_gmt":"2026-08-14T17:48:47","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/94706.html"},"modified":"2026-08-15T01:48:47","modified_gmt":"2026-08-14T17:48:47","slug":"lambda-%e9%97%ad%e5%8c%85%e5%8e%9f%e7%90%86","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/94706.html","title":{"rendered":"lambda \u95ed\u5305\u539f\u7406"},"content":{"rendered":"

\u9047\u5230\u7684\u95ee\u9898<\/h3>\n

\u5728\u5199\u4ee3\u7801\u65f6\u7ecf\u5e38\u8981\u7ed9 std::sort \u4f20\u6bd4\u8f83\u5668\u3002\u6709\u6b21\u6211\u9700\u8981\u6309"\u4e0e\u67d0\u4e2a\u9608\u503c\u8ddd\u79bb\u7684\u8fdc\u8fd1"\u6392\u5e8f：<\/p>\n

int<\/span> x =<\/span> 10<\/span>;<\/span> \/\/ \u9608\u503c<\/span><\/p>\n

bool<\/span> cmp<\/span>(<\/span>int<\/span> a,<\/span> int<\/span> b)<\/span>{<\/span>
\n return<\/span> std::<\/span>abs<\/span>(<\/span>a –<\/span> x)<\/span> <<\/span> std::<\/span>abs<\/span>(<\/span>b –<\/span> x)<\/span>;<\/span>
\n \/\/ \u53d1\u73b0\u7f16\u8bd1\u9519\u8bef：cmp \u63a5\u53d7\u4e0d\u5230 x<\/span>
\n}<\/span><\/p>\n

x \u4f20\u4e0d\u8fdb\u51fd\u6570\u4f53，\u8fd9\u662f C++ \u7684\u5e38\u8bc6\u3002\u4f46\u6362 lambda \u5199：<\/p>\n

std::<\/span>sort<\/span>(<\/span>v.<\/span>begin<\/span>(<\/span>)<\/span>,<\/span> v.<\/span>end<\/span>(<\/span>)<\/span>,<\/span>
\n [<\/span>x]<\/span>(<\/span>int<\/span> a,<\/span> int<\/span> b)<\/span>{<\/span> \/\/ \u6355\u83b7 x<\/span>
\n return<\/span> std::<\/span>abs<\/span>(<\/span>a –<\/span> x)<\/span> <<\/span> std::<\/span>abs<\/span>(<\/span>b –<\/span> x)<\/span>;<\/span>
\n }<\/span>)<\/span>;<\/span><\/p>\n

\u5047\u8bbe x\u3001cmp \u4e0e lambda \u5747\u5904\u4e8e main \u51fd\u6570\u7684\u4f5c\u7528\u57df\u4e4b\u5185，\u4f46 C++ \u4e0d\u5141\u8bb8\u666e\u901a\u51fd\u6570\u5d4c\u5957\u5b9a\u4e49\u4e8e\u51fd\u6570\u4f53\u5185，\u6240\u4ee5 cmp \u53ea\u80fd\u58f0\u660e\u4e8e\u6587\u4ef6\u4f5c\u7528\u57df，\u5176\u51fd\u6570\u4f53\u5728\u7f16\u8bd1\u671f\u5373\u4e0e main \u7684\u5c40\u90e8\u53d8\u91cf\u9694\u79bb\u3002\u800c lambda \u5219\u4f5c\u4e3a\u8868\u8fbe\u5f0f，\u53ef\u5728 main \u5185\u5c31\u5730\u521b\u5efa，\u5e76\u5c06 x \u6355\u83b7\u4e3a\u81ea\u8eab\u6210\u5458\u3002\u8fd9\u4e00\u7279\u6027\u4f53\u73b0\u4e86 lambda \u7684\u5f3a\u5927，\u672c\u6587\u5c06\u4ece\u6b64\u601d\u8003\u70b9\u51fa\u53d1，\u9010\u6b65\u5256\u6790\u8be5\u8868\u8fbe\u5f0f\u3002<\/p>\n

\n

\u4e00\u3001lambda \u7684\u5b8c\u6574\u8bed\u6cd5\u683c\u5f0f\u4e0e\u7f16\u8bd1\u671f\u672c\u8d28<\/h3>\n

lambda \u7684\u5b8c\u6574\u5f62\u6001（C++17）<\/p>\n

[<\/span>capture_list]<\/span>(<\/span>params)<\/span> mutable<\/span> noexcept<\/span>(<\/span>expr)<\/span> -><\/span> return_type {<\/span> body }<\/span><\/p>\n

\u5404\u7ec4\u6210\u90e8\u5206\u7684\u542b\u4e49\u5982\u4e0b：<\/p>\n\n\u7ec4\u6210\u542b\u4e49\u8bf4\u660e<\/tr>\n\n\n\n\n\n\n\n
capture_list<\/td>\n\u6355\u83b7\u5217\u8868<\/td>\n\u58f0\u660e\u8981\u6355\u83b7\u54ea\u4e9b\u5916\u90e8\u53d8\u91cf\u4ee5\u53ca\u6355\u83b7\u65b9\u5f0f<\/td>\n<\/tr>\n
params<\/td>\n\u53c2\u6570\u8868<\/td>\n\u4e0e\u666e\u901a\u51fd\u6570\u4e00\u81f4，\u53ef\u4ee5\u7528 auto \u6cdb\u578b\u53c2\u6570（\u6cdb\u578b lambda）<\/td>\n<\/tr>\n
mutable<\/td>\n\u53ef\u9009\u5173\u952e\u5b57<\/td>\n\u89e3\u9664 operator() \u7684 const \u5c5e\u6027<\/td>\n<\/tr>\n
noexcept<\/td>\n\u53ef\u9009\u5f02\u5e38\u8bf4\u660e<\/td>\n\u58f0\u660e\u662f\u5426\u629b\u51fa\u5f02\u5e38<\/td>\n<\/tr>\n
return_type<\/td>\n\u53ef\u9009\u8fd4\u56de\u503c\u7c7b\u578b<\/td>\nC++11 \u8d77\u652f\u6301\u81ea\u52a8\u63a8\u5bfc<\/td>\n<\/tr>\n
body<\/td>\n\u51fd\u6570\u4f53<\/td>\nlambda \u88ab\u8c03\u7528\u65f6\u6267\u884c\u7684\u4ee3\u7801<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u53bb\u6389\u5168\u90e8\u53ef\u9009\u9879，lambda \u7684\u6700\u5c0f\u5f62\u6001\u662f [capture](params){ body }\u3002<\/p>\n

\u4ee5\u6700\u7b80\u5f62\u5f0f\u4e3a\u4f8b：<\/p>\n

auto<\/span> add =<\/span> [<\/span>]<\/span>(<\/span>int<\/span> a,<\/span> int<\/span> b)<\/span>{<\/span> return<\/span> a +<\/span> b;<\/span> }<\/span>;<\/span><\/p>\n

\u7f16\u8bd1\u5668\u5c06\u5176\u5c55\u5f00\u4e3a\u4e00\u4e2a\u533f\u540d\u7ed3\u6784\u4f53（\u4e0d\u540c\u7f16\u8bd1\u5668\u751f\u6210\u7684\u5185\u90e8\u540d\u79f0\u4e0d\u540c，\u8fd9\u91cc\u4ee5 __lambda_1 \u793a\u610f）：<\/p>\n

struct<\/span> __lambda_1<\/span>{<\/span>
\n int<\/span> operator<\/span>(<\/span>)<\/span>(<\/span>int<\/span> a,<\/span> int<\/span> b)<\/span> const<\/span>{<\/span> return<\/span> a +<\/span> b;<\/span> }<\/span>
\n}<\/span>;<\/span>
\nauto<\/span> add =<\/span> __lambda_1{<\/span>}<\/span>;<\/span><\/p>\n

\u7531\u6b64\u5f97\u5230\u4e00\u4e2a\u5173\u952e\u7ed3\u8bba：lambda \u4e0d\u662f\u51fd\u6570，\u800c\u662f\u5bf9\u8c61\u3002\u51fd\u6570\u4f53\u5bf9\u5e94\u5176 operator()，\u6355\u83b7\u7684\u53d8\u91cf\u5bf9\u5e94\u5176\u6210\u5458\u53d8\u91cf；\u7f16\u8bd1\u5668\u5c06 lambda \u8868\u8fbe\u5f0f\u7ffb\u8bd1\u4e3a\u4e00\u4e2a\u533f\u540d\u7c7b，\u5e76\u5728\u8868\u8fbe\u5f0f\u51fa\u73b0\u7684\u4f4d\u7f6e\u6784\u9020\u8be5\u7c7b\u7684\u5bf9\u8c61\u2014\u2014add \u5373\u4e3a\u8be5\u6784\u9020\u6240\u5f97\u7684\u5bf9\u8c61\u5b9e\u4f8b\u3002<\/p>\n

\u4e8c\u3001\u6355\u83b7\u673a\u5236<\/h3>\n

\u95ed\u5305\u7684\u6807\u51c6\u5b9a\u4e49\u662f"\u51fd\u6570\u4e0e\u73af\u5883\u7684\u7ec4\u5408"\u3002C++ \u7684\u5b9e\u73b0\u65b9\u5f0f\u662f：\u628a\u73af\u5883（\u53ef\u89c1\u7684\u5c40\u90e8\u53d8\u91cf）\u5728\u521b\u5efa\u65f6\u523b\u6293\u53d6\u4e3a\u95ed\u5305\u5bf9\u8c61\u7684\u6210\u5458\u3002\u4e09\u79cd\u6355\u83b7\u65b9\u5f0f\u7684\u5bf9\u6bd4：<\/p>\n

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\u6355\u83b7\u65b9\u5f0f<\/p>\n

<\/span><\/p>\n

\u503c\u6355\u83b7 [x]<\/p>\n

<\/span><\/p>\n

\u5f15\u7528\u6355\u83b7 [&x]<\/p>\n

<\/span><\/p>\n

this \u6355\u83b7<\/p>\n

<\/span><\/p>\n

\u521b\u5efa\u65f6\u62f7\u8d1d\u5feb\u7167\u9ed8\u8ba4\u53ea\u8bfb mutable \u89e3\u9501<\/p>\n

<\/span><\/p>\n

\u6210\u5458\u662f\u5f15\u7528\u5b9e\u65f6\u6620\u5c04\u5916\u90e8<\/p>\n

<\/span><\/p>\n

\u6210\u5458\u662f\u6307\u9488C++17 \u53ef\u7528 [*this] \u53d6\u526f\u672c<\/p>\n

<\/span><\/p>\n

\u98ce\u9669：\u5927\u5bf9\u8c61\u62f7\u8d1d\u5f00\u9500<\/p>\n

<\/span><\/p>\n

\u98ce\u9669：\u60ac\u5782\u5f15\u7528<\/p>\n

<\/span><\/p>\n

\u98ce\u9669：this \u60ac\u5782<\/p>\n

<\/span><\/p>\n

2.1 \u503c\u6355\u83b7<\/h4>\n

int<\/span> x =<\/span> 10<\/span>;<\/span>
\nauto<\/span> l =<\/span> [<\/span>x]<\/span>{<\/span> return<\/span> x;<\/span> }<\/span>;<\/span><\/p>\n

\u5c55\u5f00\u540e：<\/p>\n

struct<\/span> __lambda_2<\/span>{<\/span>
\n int<\/span> x;<\/span> \/\/ \u6210\u5458\u53d8\u91cf，\u6784\u9020\u65f6\u4ece\u5916\u90e8 x \u62f7\u8d1d<\/span>
\n int<\/span> operator<\/span>(<\/span>)<\/span>(<\/span>)<\/span> const<\/span>{<\/span> return<\/span> x;<\/span> }<\/span>
\n}<\/span>;<\/span><\/p>\n

\u503c\u6355\u83b7\u5728 lambda \u5bf9\u8c61\u6784\u9020\u65f6\u5b8c\u6210\u4e00\u6b21\u62f7\u8d1d，\u4e4b\u540e\u4e0e\u5916\u90e8\u53d8\u91cf\u518d\u65e0\u5173\u8054\u2014\u2014\u5916\u754c\u4fee\u6539 x，\u95ed\u5305\u5185\u7684\u526f\u672c\u4e0d\u53d7\u5f71\u54cd；\u95ed\u5305\u5185（\u5728 mutable \u5141\u8bb8\u65f6）\u4fee\u6539\u526f\u672c，\u5916\u90e8\u4e5f\u770b\u4e0d\u5230\u3002<\/p>\n

2.2 \u5f15\u7528\u6355\u83b7<\/h4>\n

int<\/span> x =<\/span> 10<\/span>;<\/span>
\nauto<\/span> l =<\/span> [<\/span>&<\/span>x]<\/span>{<\/span> return<\/span> x;<\/span> }<\/span>;<\/span><\/p>\n

\u5c55\u5f00\u540e\u6210\u5458\u7c7b\u578b\u4e3a int&\u3002\u5f15\u7528\u6355\u83b7\u4e0d\u62f7\u8d1d\u6570\u636e，\u95ed\u5305\u5185\u5bf9 x \u7684\u8bbf\u95ee\u5b9e\u65f6\u6620\u5c04\u5230\u5916\u90e8\u53d8\u91cf\u3002\u4ee3\u4ef7\u662f\u751f\u547d\u5468\u671f\u4f9d\u8d56：\u82e5 x \u5148\u4e8e\u95ed\u5305\u5bf9\u8c61\u9500\u6bc1，\u95ed\u5305\u5185\u7684\u5f15\u7528\u5373\u60ac\u5782，\u8bbf\u95ee\u662f\u672a\u5b9a\u4e49\u884c\u4e3a（UB）\u3002<\/p>\n

2.3 \u521d\u59cb\u5316\u6355\u83b7：\u6355\u83b7\u4e00\u4e2a\u8868\u8fbe\u5f0f<\/h4>\n

auto<\/span> l =<\/span> [<\/span>y =<\/span> std::<\/span>make_unique<\/span><<\/span>int<\/span>><\/span><\/span><\/span>(<\/span>42<\/span>)<\/span>]<\/span>{<\/span> return<\/span> *<\/span>y;<\/span> }<\/span>;<\/span><\/p>\n

\u6b64\u65f6\u6210\u5458\u7c7b\u578b\u7531\u521d\u59cb\u5316\u8868\u8fbe\u5f0f\u63a8\u5bfc（\u8fd9\u91cc\u4e3a std::unique_ptr<int>），\u4e3a\u79fb\u52a8\u8bed\u4e49\u63d0\u4f9b\u4e86\u5165\u53e3\u3002<\/p>\n

2.4 this \u6355\u83b7\u7684\u4e24\u79cd\u5f62\u6001<\/h4>\n

\u5728\u6210\u5458\u51fd\u6570\u5185\u6355\u83b7 this，\u6210\u5458\u7c7b\u578b\u662f\u6307\u9488，\u800c\u4e0d\u662f\u5bf9\u8c61\u672c\u8eab：<\/p>\n

class<\/span> Widget<\/span>{<\/span>
\n int<\/span> value_;<\/span>
\npublic<\/span>:<\/span>
\n auto<\/span> get_lambda<\/span>(<\/span>)<\/span>{<\/span>
\n return<\/span> [<\/span>this<\/span>]<\/span>{<\/span> return<\/span> value_;<\/span> }<\/span>;<\/span> \/\/ \u6355\u83b7 this \u6307\u9488<\/span>
\n }<\/span>
\n}<\/span>;<\/span><\/p>\n

\u8fd9\u5e26\u6765\u4e00\u4e2a\u7ecf\u5178\u9690\u60a3：\u82e5 Widget \u5bf9\u8c61\u5148\u4e8e lambda \u9500\u6bc1，lambda \u5185\u7684 this \u60ac\u5782\u3002C++17 \u63d0\u4f9b [*this] \u6355\u83b7\u5bf9\u8c61\u526f\u672c：<\/p>\n

auto<\/span> get_lambda<\/span>(<\/span>)<\/span>{<\/span>
\n return<\/span> [<\/span>*<\/span>this<\/span>]<\/span>{<\/span> return<\/span> value_;<\/span> }<\/span>;<\/span> \/\/ \u6355\u83b7\u5bf9\u8c61\u526f\u672c，\u6210\u5458\u7c7b\u578b\u4e3a Widget<\/span>
\n}<\/span>;<\/span><\/p>\n

\u4ee3\u4ef7\u662f\u5bf9\u8c61\u62f7\u8d1d\u7684\u5f00\u9500，\u6362\u6765\u751f\u547d\u5468\u671f\u4e0a\u7684\u5b89\u5168\u3002<\/p>\n

2.5 \u9ed8\u8ba4\u6355\u83b7 [=] \u4e0e [&]<\/h4>\n

[=] \u5bf9\u5168\u90e8\u53ef\u89c1\u81ea\u52a8\u53d8\u91cf\u6309\u503c\u6355\u83b7，[&] \u6309\u5f15\u7528\u6355\u83b7\u3002\u4e24\u8005\u662f\u8bed\u6cd5\u7cd6，\u7b49\u4ef7\u4e8e\u9010\u4e00\u5217\u51fa\u6355\u83b7\u9879\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f：this \u6307\u9488\u5728\u4efb\u4f55\u6210\u5458\u51fd\u6570\u4e2d\u90fd\u662f"\u88ab\u6309\u503c\u6355\u83b7\u7684\u81ea\u52a8\u53d8\u91cf"，\u56e0\u6b64\u6210\u5458\u51fd\u6570\u5185\u5199 [=] \u5b9e\u9645\u4f1a\u9690\u5f0f\u6355\u83b7 this，\u8fd9\u662f [=] \u60ac\u5782\u98ce\u9669\u7684\u9ad8\u53d1\u573a\u666f，\u4ee3\u7801\u5ba1\u67e5\u65f6\u5e94\u683c\u5916\u7559\u610f\u3002<\/p>\n

\u4e09\u3001operator() \u7684 const \u8bed\u4e49\u4e0e mutable<\/h3>\n

\u9ed8\u8ba4\u60c5\u51b5\u4e0b，\u533f\u540d\u7c7b\u7684 operator() \u662f const \u6210\u5458\u51fd\u6570\u3002\u8fd9\u610f\u5473\u7740\u503c\u6355\u83b7\u7684\u6210\u5458\u5728\u95ed\u5305\u5185\u662f\u53ea\u8bfb\u7684：<\/p>\n

int<\/span> x =<\/span> 10<\/span>;<\/span>
\nauto<\/span> l =<\/span> [<\/span>x]<\/span>{<\/span> x++<\/span>;<\/span> }<\/span>;<\/span> \/\/ \u7f16\u8bd1\u9519\u8bef：\u4e0d\u80fd\u4fee\u6539 const \u6210\u5458<\/span><\/p>\n

\u8fd9\u4e00\u8bbe\u8ba1\u7b26\u5408\u95ed\u5305\u7684\u51fd\u6570\u5f0f\u8bed\u4e49：\u503c\u6355\u83b7\u4ea7\u751f\u7684\u662f\u73af\u5883\u5feb\u7167，\u5feb\u7167\u5e94\u4e0d\u53ef\u53d8，lambda \u8868\u73b0\u4e3a"\u7eaf\u51fd\u6570"\u3002\u82e5\u786e\u5b9e\u9700\u8981\u4fee\u6539\u526f\u672c，\u52a0 mutable：<\/p>\n

int<\/span> x =<\/span> 10<\/span>;<\/span>
\nauto<\/span> l =<\/span> [<\/span>x]<\/span>(<\/span>)<\/span> mutable<\/span> {<\/span> x++<\/span>;<\/span> }<\/span>;<\/span> \/\/ \u5408\u6cd5：\u4fee\u6539\u7684\u662f\u526f\u672c<\/span>
\n\/\/ \u5916\u90e8 x \u4ecd\u4e3a 10<\/span><\/p>\n

\u9700\u8981\u5f3a\u8c03\u7684\u662f：mutable \u4fee\u6539\u7684\u662f\u95ed\u5305\u5185\u7684\u526f\u672c，\u4e0e\u5916\u90e8\u53d8\u91cf\u65e0\u5173\u3002<\/p>\n

\u56db\u3001\u65e0\u6355\u83b7 lambda \u5230\u51fd\u6570\u6307\u9488\u7684\u9000\u5316<\/h3>\n

\u51fd\u6570\u6307\u9488\u662f\u4e00\u79cd\u53d8\u91cf，\u5176\u503c\u4e3a\u67d0\u6bb5\u51fd\u6570\u4ee3\u7801\u7684\u5165\u53e3\u5730\u5740\u3002\u8c03\u7528\u51fd\u6570\u6307\u9488\u65f6，\u7a0b\u5e8f\u8df3\u8f6c\u81f3\u8be5\u5730\u5740\u6267\u884c；\u51fd\u6570\u6240\u9700\u7684\u53c2\u6570\u7531\u8c03\u7528\u65b9\u5728\u8c03\u7528\u70b9\u4f20\u5165，\u51fd\u6570\u6307\u9488\u672c\u8eab\u4e0d\u643a\u5e26\u4efb\u4f55\u4e0e\u6570\u636e\u76f8\u5173\u7684\u4fe1\u606f\u3002<\/p>\n

lambda \u7684 operator() \u662f\u6210\u5458\u51fd\u6570\u3002\u5bf9\u4e8e\u6355\u83b7\u4e86\u53d8\u91cf\u7684 lambda，\u5176 operator() \u5728\u6267\u884c\u65f6\u9700\u8981\u8bbf\u95ee\u95ed\u5305\u5bf9\u8c61\u7684\u6210\u5458（\u5982\u503c\u6355\u83b7\u53d8\u91cf\u7684\u526f\u672c），\u800c\u6210\u5458\u8bbf\u95ee\u4f9d\u8d56\u5bf9\u8c61\u5730\u5740（this）\u3002\u51fd\u6570\u6307\u9488\u7684\u8c03\u7528\u4e0d\u63d0\u4f9b\u5bf9\u8c61\u5730\u5740\u2014\u2014\u8c03\u7528\u65b9\u4ec5\u8df3\u8f6c\u81f3\u4ee3\u7801\u5730\u5740，\u4e0d\u643a\u5e26\u4efb\u4f55\u5bf9\u8c61\u4fe1\u606f\u3002\u56e0\u6b64，\u6355\u83b7\u4e86\u53d8\u91cf\u7684 lambda \u65e0\u6cd5\u8f6c\u6362\u4e3a\u51fd\u6570\u6307\u9488：\u8f6c\u6362\u540e\u6210\u5458\u65e0\u4ece\u8bbf\u95ee，\u4ee3\u7801\u65e0\u6cd5\u6b63\u786e\u6267\u884c\u3002<\/p>\n

\u65e0\u6355\u83b7 lambda \u7684 operator() \u4e0d\u8bbf\u95ee\u4efb\u4f55\u6210\u5458\u53d8\u91cf，\u5176\u6267\u884c\u4e0d\u4f9d\u8d56\u5bf9\u8c61\u5730\u5740，\u5373\u4f7f\u4e0d\u5b58\u5728\u95ed\u5305\u5bf9\u8c61，\u4ee3\u7801\u4ea6\u53ef\u72ec\u7acb\u8fd0\u884c\u3002\u6b64\u65f6 lambda \u4e0e\u666e\u901a\u51fd\u6570\u5728\u884c\u4e3a\u4e0a\u65e0\u5dee\u522b，\u6807\u51c6\u56e0\u6b64\u5141\u8bb8\u5176\u5411\u540c\u7b7e\u540d\u7684\u51fd\u6570\u6307\u9488\u9690\u5f0f\u8f6c\u6362：<\/p>\n

void<\/span> (<\/span>*<\/span>fp)<\/span>(<\/span>)<\/span> =<\/span> [<\/span>]<\/span>{<\/span>}<\/span>;<\/span> \/\/ \u5408\u6cd5<\/span>
\nint<\/span> x =<\/span> 10<\/span>;<\/span>
\nvoid<\/span> (<\/span>*<\/span>fp2)<\/span>(<\/span>)<\/span> =<\/span> [<\/span>x]<\/span>{<\/span>}<\/span>;<\/span> \/\/ \u975e\u6cd5<\/span><\/p>\n

\u65e0\u6355\u83b7 lambda \u7684\u533f\u540d\u7c7b\u4e0d\u542b\u6210\u5458\u53d8\u91cf，\u5c5e\u4e8e\u7a7a\u7c7b，C++ \u89c4\u5b9a\u4efb\u4f55\u5bf9\u8c61\u81f3\u5c11\u5360\u7528\u4e00\u5b57\u8282\u7684\u5b58\u50a8，\u4fdd\u8bc1\u4e0d\u540c\u5bf9\u8c61\u5177\u6709\u4e0d\u540c\u5730\u5740，\u56e0\u6b64 lambda \u5bf9\u8c61\u672c\u8eab\u5360 1 \u5b57\u8282\u3002\u8f6c\u6362\u4e3a\u51fd\u6570\u6307\u9488\u540e，\u5bf9\u8c61\u4e0d\u518d\u5b58\u5728，\u8c03\u7528\u76f4\u63a5\u4f7f\u7528\u4ee3\u7801\u5730\u5740，"\u65e0\u72b6\u6001"\u7279\u6027\u7531\u6b64\u4f53\u73b0\u3002<\/p>\n

\u4e94\u3001\u7ed3\u5408std::function<\/h3>\n

lambda \u7c7b\u578b\u552f\u4e00\u4e14\u5404\u4e0d\u76f8\u540c，\u800c\u56de\u8c03\u5bb9\u5668\u3001\u4e8b\u4ef6\u7cfb\u7edf\u3001\u4efb\u52a1\u961f\u5217\u9700\u8981"\u5b58\u653e\u4efb\u610f\u53ef\u8c03\u7528\u5bf9\u8c61"\u3002std::function \u901a\u8fc7\u7c7b\u578b\u64e6\u9664\u5b9e\u73b0\u8fd9\u4e00\u70b9：\u5bb9\u5668\u53ea\u4fdd\u7559\u7b7e\u540d（\u5982 int(int,int)），\u62b9\u6389\u5177\u4f53\u7c7b\u578b，\u5185\u90e8\u901a\u8fc7\u6307\u5411\u5b58\u50a8\u7684\u8c03\u7528\u76ee\u6807\u95f4\u63a5\u8c03\u7528\u3002<\/p>\n

std::<\/span>function<<\/span>int<\/span>(<\/span>int<\/span>,<\/span>int<\/span>)<\/span>><\/span> f;<\/span>
\nf =<\/span> [<\/span>]<\/span>(<\/span>int<\/span> a,<\/span> int<\/span> b)<\/span>{<\/span> return<\/span> a +<\/span> b;<\/span> }<\/span>;<\/span>
\nf<\/span>(<\/span>3<\/span>,<\/span> 4<\/span>)<\/span>;<\/span> \/\/ \u8fd4\u56de 7<\/span><\/p>\n

\u7c7b\u578b\u64e6\u9664\u7684\u4ee3\u4ef7\u662f\u663e\u8457\u7684，\u5176\u4e00，\u8c03\u7528\u4ece\u7f16\u8bd1\u671f\u76f4\u63a5\u8c03\u7528\u9000\u5316\u4e3a\u8fd0\u884c\u65f6\u95f4\u63a5\u8df3\u8f6c，\u51fa\u73b0\u65e0\u6cd5\u5185\u8054\u6027\u80fd\u635f\u5931；\u5176\u4e8c，std::function \u5bf9\u5c0f\u5bf9\u8c61\u6709\u5c0f\u578b\u7f13\u51b2\u4f18\u5316（SBO），\u7f13\u51b2\u5bb9\u7eb3\u4e0d\u4e0b\u7684\u53ef\u8c03\u7528\u5bf9\u8c61\u9700\u8981\u5806\u5206\u914d，\u62f7\u8d1d\u5373\u4ea7\u751f\u5206\u914d\u5f00\u9500；\u5176\u4e09，\u7a7a std::function \u88ab\u8c03\u7528\u65f6\u629b\u51fa std::bad_function_call，\u5f15\u5165\u8fd0\u884c\u65f6\u5206\u652f\u3002<\/p>\n

\u9009\u62e9\u539f\u5219\u7531\u6b64\u660e\u786e：\u7c7b\u578b\u5728\u7f16\u8bd1\u671f\u53ef\u77e5\u65f6，\u7528 auto \u4fdd\u5b58 lambda（\u96f6\u5f00\u9500\u3001\u53ef\u5185\u8054）；\u53ea\u6709\u786e\u5b9e\u9700\u8981"\u591a\u6001\u5730\u5b58\u653e\u53ef\u8c03\u7528\u5bf9\u8c61"\u65f6\u624d\u4f7f\u7528 std::function\u3002<\/p>\n

\u516d\u3001\u751f\u547d\u5468\u671f\u9677\u9631<\/h3>\n

\u95ed\u5305\u673a\u5236\u7684\u5168\u90e8\u98ce\u9669\u96c6\u4e2d\u5728\u4e00\u70b9：\u95ed\u5305\u5bf9\u8c61\u5b58\u6d3b\u671f\u95f4，\u88ab\u6355\u83b7\u5bf9\u8c61\u5fc5\u987b\u540c\u6837\u5b58\u6d3b\u3002\u5e38\u89c1\u9ad8\u53d1\u573a\u666f：<\/p>\n

\u4e00，\u5f15\u7528\u6355\u83b7\u60ac\u5782\u3002\u51fd\u6570\u8fd4\u56de lambda \u65f6，lambda \u5185\u5f15\u7528\u7684\u5c40\u90e8\u53d8\u91cf\u5df2\u7ecf\u9500\u6bc1：<\/p>\n

std::<\/span>function<<\/span>int<\/span>(<\/span>)<\/span>><\/span> make<\/span>(<\/span>)<\/span>{<\/span>
\n int<\/span> x =<\/span> 42<\/span>;<\/span>
\n return<\/span> [<\/span>&<\/span>x]<\/span>{<\/span> return<\/span> x;<\/span> }<\/span>;<\/span> \/\/ x \u5df2\u9500\u6bc1，\u8c03\u7528\u5373\u672a\u5b9a\u4e49\u884c\u4e3a<\/span>
\n}<\/span><\/p>\n

\u4e8c，this \u6355\u83b7\u60ac\u5782\u3002\u5bf9\u8c61\u5148\u4e8e\u95ed\u5305\u6790\u6784（\u5982\u95ed\u5305\u88ab\u5f02\u6b65\u6267\u884c），\u8bbf\u95ee\u5373\u5d29\u6e83\u6216\u8bfb\u5230\u5783\u573e\u6570\u636e\u3002<\/p>\n

\u5e94\u5bf9\u65b9\u6848\u662f\u8ba9\u6355\u83b7\u5bf9\u8c61\u4e0e\u95ed\u5305\u5171\u4eab\u751f\u547d\u5468\u671f：\u5728\u5e76\u53d1\u573a\u666f\u4e2d，\u6700\u5e38\u7528\u7684\u624b\u6bb5\u662f\u6355\u83b7 std::shared_ptr\u2014\u2014\u95ed\u5305\u6301\u6709\u5f15\u7528\u8ba1\u6570，\u6355\u83b7\u5bf9\u8c61\u5b58\u6d3b\u671f\u88ab\u95ed\u5305\u5ef6\u957f，\u76f4\u5230\u6700\u540e\u4e00\u4e2a\u95ed\u5305\u9500\u6bc1\u3002<\/p>\n

\u4e03\u3001\u5e76\u53d1\u573a\u666f\u4e2d\u7684\u5e94\u7528<\/h3>\n

lambda \u7684\u95ed\u5305\u80fd\u529b\u5728\u5e76\u53d1\u7f16\u7a0b\u4e2d\u627f\u62c5\u4e86\u6838\u5fc3\u89d2\u8272\u3002\u4ee5\u7ebf\u7a0b\u6c60\u4e3a\u4f8b，\u4efb\u52a1\u88ab\u62cd\u6241\u4e3a"\u65e0\u53c2\u65e0\u8fd4\u56de\u503c\u7684\u52a8\u4f5c"\u5b58\u50a8\u4e8e\u961f\u5217：<\/p>\n

std::<\/span>queue<<\/span>std::<\/span>function<<\/span>void<\/span>(<\/span>)<\/span>>><\/span> tasks;<\/span><\/p>\n

\u63d0\u4ea4\u7aef\u4efb\u610f\u7b7e\u540d\u7684\u8c03\u7528\u88ab enqueue \u6536\u53e3：<\/p>\n

template<\/span><<\/span>class<\/span> F<\/span>,<\/span> class<\/span>.<\/span>.<\/span>.<\/span> Args><\/span>
\nauto<\/span> enqueue<\/span>(<\/span>F&&<\/span> f,<\/span> Args&&<\/span>.<\/span>.<\/span>.<\/span> args)<\/span>
\n -><\/span> std::<\/span>future<<\/span>std::<\/span>invoke_result_t<<\/span>F,<\/span> Args.<\/span>.<\/span>.<\/span>>><\/span>{<\/span>
\n using<\/span> return_type =<\/span> std::<\/span>invoke_result_t<<\/span>F,<\/span> Args.<\/span>.<\/span>.<\/span>><\/span>;<\/span>
\n auto<\/span> task =<\/span> std::<\/span>make_shared<\/span><<\/span>std::<\/span>packaged_task<<\/span>return_type<\/span>(<\/span>)<\/span>>><\/span><\/span><\/span>(<\/span>
\n std::<\/span>bind<\/span>(<\/span>std::<\/span>forward<\/span><<\/span>F><\/span><\/span><\/span>(<\/span>f)<\/span>,<\/span> std::<\/span>forward<\/span><<\/span>Args><\/span><\/span><\/span>(<\/span>args)<\/span>.<\/span>.<\/span>.<\/span>)<\/span>)<\/span>;<\/span>
\n std::<\/span>future<<\/span>return_type><\/span> res =<\/span> task-><\/span>get_future<\/span>(<\/span>)<\/span>;<\/span>
\n {<\/span>
\n std::<\/span>lock_guard<<\/span>std::<\/span>mutex><\/span> lock<\/span>(<\/span>queue_mutex)<\/span>;<\/span>
\n tasks.<\/span>emplace<\/span>(<\/span>[<\/span>task]<\/span>{<\/span> (<\/span>*<\/span>task)<\/span>(<\/span>)<\/span>;<\/span> }<\/span>)<\/span>;<\/span>
\n }<\/span>
\n cv.<\/span>notify_one<\/span>(<\/span>)<\/span>;<\/span>
\n return<\/span> res;<\/span>
\n}<\/span><\/p>\n

\u4efb\u52a1\u4ece\u63d0\u4ea4\u5230\u83b7\u53d6\u7ed3\u679c\u7684\u5b8c\u6574\u751f\u547d\u5468\u671f：<\/p>\n

futureworker\u7ebf\u7a0b\u4efb\u52a1\u961f\u5217\u63d0\u4ea4\u8005futureworker\u7ebf\u7a0b\u4efb\u52a1\u961f\u5217\u63d0\u4ea4\u8005#mermaid-svg-U9WQ1oD2S2pcxXtZ{font-family:\\”trebuchet ms\\”,verdana,arial,sans-serif;font-size:16px;fill:#333;}@keyframes edge-animation-frame{from{stroke-dashoffset:0;}}@keyframes dash{to{stroke-dashoffset:0;}}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-animation-slow{stroke-dasharray:9,5!important;stroke-dashoffset:900;animation:dash 50s linear infinite;stroke-linecap:round;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-animation-fast{stroke-dasharray:9,5!important;stroke-dashoffset:900;animation:dash 20s linear infinite;stroke-linecap:round;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .error-icon{fill:#552222;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .error-text{fill:#552222;stroke:#552222;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-thickness-normal{stroke-width:1px;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-thickness-thick{stroke-width:3.5px;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-pattern-solid{stroke-dasharray:0;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-thickness-invisible{stroke-width:0;fill:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-pattern-dashed{stroke-dasharray:3;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .edge-pattern-dotted{stroke-dasharray:2;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .marker{fill:#333333;stroke:#333333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .marker.cross{stroke:#333333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ svg{font-family:\\”trebuchet ms\\”,verdana,arial,sans-serif;font-size:16px;}#mermaid-svg-U9WQ1oD2S2pcxXtZ p{margin:0;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actor{stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);fill:#ECECFF;}#mermaid-svg-U9WQ1oD2S2pcxXtZ text.actor>tspan{fill:black;stroke:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actor-line{stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);}#mermaid-svg-U9WQ1oD2S2pcxXtZ .innerArc{stroke-width:1.5;stroke-dasharray:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .messageLine0{stroke-width:1.5;stroke-dasharray:none;stroke:#333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .messageLine1{stroke-width:1.5;stroke-dasharray:2,2;stroke:#333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ #arrowhead path{fill:#333;stroke:#333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .sequenceNumber{fill:white;}#mermaid-svg-U9WQ1oD2S2pcxXtZ #sequencenumber{fill:#333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ #crosshead path{fill:#333;stroke:#333;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .messageText{fill:#333;stroke:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .labelBox{stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);fill:#ECECFF;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .labelText,#mermaid-svg-U9WQ1oD2S2pcxXtZ .labelText>tspan{fill:black;stroke:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .loopText,#mermaid-svg-U9WQ1oD2S2pcxXtZ .loopText>tspan{fill:black;stroke:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .loopLine{stroke-width:2px;stroke-dasharray:2,2;stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);fill:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);}#mermaid-svg-U9WQ1oD2S2pcxXtZ .note{stroke:#aaaa33;fill:#fff5ad;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .noteText,#mermaid-svg-U9WQ1oD2S2pcxXtZ .noteText>tspan{fill:black;stroke:none;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .activation0{fill:#f4f4f4;stroke:#666;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .activation1{fill:#f4f4f4;stroke:#666;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .activation2{fill:#f4f4f4;stroke:#666;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actorPopupMenu{position:absolute;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actorPopupMenuPanel{position:absolute;fill:#ECECFF;box-shadow:0px 8px 16px 0px rgba(0,0,0,0.2);filter:drop-shadow(3px 5px 2px rgb(0 0 0 \/ 0.4));}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actor-man line{stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);fill:#ECECFF;}#mermaid-svg-U9WQ1oD2S2pcxXtZ .actor-man circle,#mermaid-svg-U9WQ1oD2S2pcxXtZ line{stroke:hsl(259.6261682243, 59.7765363128%, 87.9019607843%);fill:#ECECFF;stroke-width:2px;}#mermaid-svg-U9WQ1oD2S2pcxXtZ :root{–mermaid-font-family:\\”trebuchet ms\\”,verdana,arial,sans-serif;}\u65f6\u95f4\u89e3\u8026（\u53ef\u9694\u4efb\u610f\u4e45）enqueue \u6253\u5305\u4efb\u52a1\u5165\u961f\u62ff\u5230 future（\u7ee7\u7eed\u5e72\u522b\u7684）notify_one \u5524\u9192\u9501\u5916\u6267\u884c (*task)()\u7ed3\u679c\u81ea\u52a8\u5199\u5165 shared statefuture.get() \u89e3\u9664\u963b\u585e<\/p>\n

\u95ed\u5305\u673a\u5236\u5728\u6b64\u6709\u4e09\u5904\u5178\u578b\u5e94\u7528：<\/p>\n

  • \u53c2\u6570\u7ed1\u5b9a：std::bind \u5c06\u51fd\u6570\u4e0e\u5b9e\u53c2\u7ed1\u5b9a\u4e3a\u65e0\u53c2\u53ef\u8c03\u7528\u5bf9\u8c61，\u4efb\u52a1\u5f97\u4ee5\u7edf\u4e00\u4e3a void() \u5f62\u6001\u8fdb\u5165\u961f\u5217，\u961f\u5217\u4ec5\u9700\u4f9d\u8d56\u5355\u4e00\u63a5\u53e3\u3002<\/li>\n
  • \u6355\u83b7\u5171\u4eab\u751f\u547d\u5468\u671f：packaged_task \u4e0d\u53ef\u62f7\u8d1d，\u6545\u4ee5 std::shared_ptr \u5305\u88f9，lambda \u6355\u83b7 shared_ptr \u526f\u672c\u2014\u2014\u4efb\u52a1\u672c\u4f53\u4ec5\u5b58\u4e00\u4efd，lambda \u5728\u961f\u5217\u4e0e worker \u4e4b\u95f4\u7684\u62f7\u8d1d\u4e0e\u79fb\u52a8\u5747\u65e0\u98ce\u9669，\u4e14 shared_ptr \u4fdd\u8bc1\u4efb\u52a1\u5728\u6267\u884c\u524d\u4e0d\u4f1a\u88ab\u9500\u6bc1\u3002<\/li>\n
  • \u5b8c\u7f8e\u8f6c\u53d1：std::forward<F>(f), std::forward<Args>(args)… \u4fdd\u6301\u5b9e\u53c2\u7684\u5de6\u53f3\u503c\u5c5e\u6027，move-only \u7c7b\u578b（\u5982 unique_ptr）\u7684\u5b9e\u53c2\u5f97\u4ee5\u539f\u6837\u8fdb\u5165\u4efb\u52a1\u3002<\/li>\n

    \u503c\u5f97\u6ce8\u610f\u7684\u7ec6\u8282\u662f：lambda \u6355\u83b7 shared_ptr \u5c5e\u4e8e\u503c\u6355\u83b7，\u6355\u83b7\u7684\u662f\u6307\u9488\u672c\u8eab；\u4efb\u52a1\u771f\u6b63\u7684\u6267\u884c\u671f（worker \u53d6\u51fa\u5e76\u8c03\u7528）\u53ef\u80fd\u8fdc\u665a\u4e8e\u63d0\u4ea4\u65f6\u523b，\u4f46 shared_ptr \u7684\u751f\u547d\u5468\u671f\u5ef6\u957f\u673a\u5236\u4fdd\u8bc1\u4e0d\u4f1a\u5f15\u5165\u60ac\u5782\u3002\u8fd9\u6b63\u662f\u95ed\u5305\u673a\u5236\u5728\u5e76\u53d1\u7a0b\u5e8f\u8bbe\u8ba1\u4e2d\u7684\u4ef7\u503c\u6240\u5728\u2014\u2014\u628a\u4e00\u6bb5\u4ee3\u7801\u4e0e\u5176\u9700\u8981\u7684\u73af\u5883\u6253\u5305\u6210\u53ef\u4f20\u9012\u3001\u53ef\u5ef6\u8fdf\u6267\u884c\u7684\u5bf9\u8c61\u3002<\/p>\n

    \u603b\u7ed3<\/h3>\n

    lambda \u4e4b\u6240\u4ee5\u80fd\u5e26\u8d70\u666e\u901a\u51fd\u6570\u5e26\u4e0d\u8d70\u7684\u5c40\u90e8\u53d8\u91cf，\u6839\u6e90\u5728\u4e8e\u5b83\u7684\u5b9e\u73b0\u5f62\u6001：lambda \u4e0d\u662f\u51fd\u6570，\u800c\u662f\u7f16\u8bd1\u5668\u751f\u6210\u7684\u533f\u540d\u7c7b\u5bf9\u8c61，\u51fd\u6570\u4f53\u5bf9\u5e94 operator()，\u6355\u83b7\u7684\u53d8\u91cf\u5bf9\u5e94\u6210\u5458\u53d8\u91cf，\u521b\u5efa\u65f6\u523b\u5c06\u5916\u90e8\u53d8\u91cf\u6293\u4e3a\u6210\u5458，\u4e4b\u540e\u968f\u5bf9\u8c61\u643a\u5e26\u4f20\u9012\u3002<\/p>\n

    \u56de\u5230\u5f00\u5934\u7684\u95ee\u9898：std::sort \u7684\u6bd4\u8f83\u5668\u4e4b\u6240\u4ee5\u80fd\u6355\u83b7\u9608\u503c x，\u6b63\u662f\u56e0\u4e3a lambda \u5728\u521b\u5efa\u65f6\u628a x \u62f7\u8d1d\u6210\u4e86\u81ea\u5df1\u7684\u6210\u5458，\u73af\u5883\u968f\u5bf9\u8c61\u8d70，\u8c03\u7528\u53ea\u4f20\u53d8\u5316\u7684\u53c2\u6570\u3002<\/p>\n

    \u672c\u4eba\u80fd\u529b\u6709\u9650，\u6587\u7ae0\u5982\u6709\u9519\u8bef\u6216\u9057\u6f0f\u4e4b\u5904，\u6b22\u8fce\u6307\u6b63\u3002<\/p>\n

    \n

    \u53c2\u8003\u8d44\u6599<\/h3>\n
  • cppreference \u2014 Lambda expressions<\/li>\n
  • cppreference \u2014 std::function<\/li>\n
  • \u300aEffective Modern C++\u300b<\/li>\n
  • \u300a\u6df1\u5165\u7406\u89e3\u8ba1\u7b97\u673a\u7cfb\u7edf\u300b<\/li>\n","protected":false},"excerpt":{"rendered":"

    \u9047\u5230\u7684\u95ee\u9898
    \n\u5728\u5199\u4ee3\u7801\u65f6\u7ecf\u5e38\u8981\u7ed9 std::sort \u4f20\u6bd4\u8f83\u5668\u3002\u6709\u6b21\u6211\u9700\u8981\u6309\\”\u4e0e\u67d0\u4e2a\u9608\u503c\u8ddd\u79bb\u7684\u8fdc\u8fd1\\”\u6392\u5e8f：
    \nint x 10; \/\/ \u9608\u503cbool cmp(int a, int b){ return std::abs(a – x) < std::abs(b – x);\/\/ \u53d1\u73b0\u7f16\u8bd1\u9519\u8bef：cmp \u63a5\u53d7\u4e0d\u5230 x
    \n}x \u4f20\u4e0d\u8fdb\u51fd\u6570\u4f53，\u8fd9\u662f C \u7684\u5e38\u8bc6\u3002\u4f46\u6362 la<\/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],"topic":[],"class_list":["post-94706","post","type-post","status-publish","format-standard","hentry","category-server","tag-c"],"yoast_head":"\nlambda \u95ed\u5305\u539f\u7406 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/94706.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"lambda \u95ed\u5305\u539f\u7406 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u9047\u5230\u7684\u95ee\u9898 \u5728\u5199\u4ee3\u7801\u65f6\u7ecf\u5e38\u8981\u7ed9 std::sort \u4f20\u6bd4\u8f83\u5668\u3002\u6709\u6b21\u6211\u9700\u8981\u6309"\u4e0e\u67d0\u4e2a\u9608\u503c\u8ddd\u79bb\u7684\u8fdc\u8fd1"\u6392\u5e8f： int x 10; 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