{"id":64076,"date":"2025-05-03T22:22:26","date_gmt":"2025-05-03T14:22:26","guid":{"rendered":"https:\/\/fwq.ai\/blog\/?p=64076"},"modified":"2025-05-03T22:23:34","modified_gmt":"2025-05-03T14:23:34","slug":"%e6%8e%a2%e7%b4%a2-c23-%e7%9a%84-stdbind_back%ef%bc%9a%e5%87%bd%e6%95%b0%e7%bb%91%e5%ae%9a%e5%86%8d%e8%bf%9b%e5%8c%96%e4%b8%8e%e6%9c%8d%e5%8a%a1%e5%99%a8%e5%ba%94%e7%94%a8%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/64076\/","title":{"rendered":"\u63a2\u7d22 C++23 \u7684 std::bind_back\uff1a\u51fd\u6570\u7ed1\u5b9a\u518d\u8fdb\u5316\u4e0e\u670d\u52a1\u5668\u5e94\u7528\u5b9e\u8df5"},"content":{"rendered":"

 <\/p><\/blockquote>\n

\u4e00\u3001\u51fd\u6570\u7ed1\u5b9a\u7684\u6f14\u8fdb\u8def\u5f84\uff1a\u4ece bind \u5230 bind_back<\/h2>\n

\u5728\u73b0\u4ee3 C++ \u4e2d\uff0c\u51fd\u6570\u7ed1\u5b9a\u662f\u5b9e\u73b0\u5f02\u6b65\u56de\u8c03\u3001\u5ef6\u8fdf\u8ba1\u7b97\u4e0e\u53c2\u6570\u5c01\u88c5\u7684\u91cd\u8981\u5de5\u5177\u3002\u4ece\u65e9\u671f\u7684 std::bind<\/code> \u5230 C++20 \u7684 std::bind_front<\/code>\uff0c\u518d\u5230 C++23 \u7684 std::bind_back<\/code>\uff0c\u6bcf\u4e00\u6b21\u6f14\u8fdb\u90fd\u4e3a\u5f00\u53d1\u8005\u63d0\u4f9b\u4e86\u66f4\u5f3a\u7684\u62bd\u8c61\u80fd\u529b\u3002<\/p>\n

1. std::bind\uff08C++11\uff09<\/h3>\n

std::bind<\/code> \u5141\u8bb8\u5f00\u53d1\u8005\u7ed1\u5b9a\u51fd\u6570\u53c2\u6570\u81f3\u4efb\u610f\u4f4d\u7f6e\uff0c\u7ed3\u5408\u5360\u4f4d\u7b26\u7075\u6d3b\u6784\u5efa\u51fd\u6570\u5bf9\u8c61\uff1a<\/p>\n

#include <functional>\r\n#include <iostream>\r\nusing namespace std::placeholders;\r\n\r\ndouble divide(double a, double b) { return a \/ b; }\r\n\r\nint main() {\r\n    auto func1 = std::bind(divide, _1, _2); \/\/ \u4e0d\u7ed1\u5b9a\u4efb\u4f55\u53c2\u6570\r\n    auto func2 = std::bind(divide, 1000, _1); \/\/ \u9884\u8bbe\u7b2c\u4e00\u4e2a\u53c2\u6570\u4e3a 1000\r\n    std::cout << func2(5) << std::endl; \/\/ \u8f93\u51fa 200\r\n}\r\n<\/code><\/pre>\n
\u8fd9\u79cd\u65b9\u5f0f\u867d\u7136\u5f3a\u5927\uff0c\u4f46\u5728\u53ef\u8bfb\u6027\u548c\u53c2\u6570\u4f4d\u7f6e\u63a7\u5236\u4e0a\u5b58\u5728\u4e00\u5b9a\u7684\u590d\u6742\u5ea6\u3002<\/p>\n
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2. std::bind_front\uff08C++20\uff09<\/h3>\n
\u4e3a\u7b80\u5316\u5e38\u89c1\u7684\u201c\u524d\u7f6e\u7ed1\u5b9a\u201d\u573a\u666f\uff0cC++20 \u63a8\u51fa\u4e86 std::bind_front<\/code>\uff1a<\/p>\n
auto func = std::bind_front(divide, 1000);\r\nstd::cout << func(5) << std::endl; \/\/ \u8f93\u51fa 200\uff0c\u76f8\u5f53\u4e8e divide(1000, 5)\r\n<\/code><\/pre>\n
\u901a\u8fc7\u7ed1\u5b9a\u524d\u7f6e\u53c2\u6570\uff0cstd::bind_front<\/code> \u66f4\u9002\u5408\u6784\u5efa\u51fd\u6570\u9002\u914d\u5668\u4e0e\u56de\u8c03\u5305\u88c5\u5668\u3002<\/p>\n
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3. std::bind_back\uff08C++23\uff09<\/h3>\n
C++23 \u5f15\u5165\u7684 std::bind_back<\/code> \u5219\u805a\u7126\u4e8e\u201c\u540e\u7f6e\u7ed1\u5b9a\u201d\uff0c\u5373\u5c06\u53c2\u6570\u7ed1\u5b9a\u81f3\u51fd\u6570\u5c3e\u90e8\uff1a<\/p>\n
auto func = std::bind_back(divide, 5);\r\nstd::cout << func(1000) << std::endl; \/\/ \u8f93\u51fa 200\uff0c\u76f8\u5f53\u4e8e divide(1000, 5)\r\n<\/code><\/pre>\n
\u5176\u8bed\u4e49\u4e0a\u7b49\u4ef7\u4e8e\uff1a<\/p>\n
std::invoke(f, call_args..., bound_args...);\r\n<\/code><\/pre>\n
\n
\u4e8c\u3001std::bind_back \u7684\u4f7f\u7528\u4f18\u52bf<\/h2>\n
1. \u5f02\u6b65\u4e0e\u7ebf\u7a0b\u573a\u666f\u4e0b\u7684\u7b80\u5316<\/h3>\n
\u5728\u591a\u7ebf\u7a0b\u7f16\u7a0b\u4e2d\uff0c\u5e38\u9700\u5c06\u90e8\u5206\u53c2\u6570\u5c01\u88c5\u4e3a\u65e0\u53c2\u56de\u8c03\uff0cstd::bind_back<\/code> \u53ef\u7b80\u6d01\u5b8c\u6210\uff1a<\/p>\n
#include <thread>\r\nvoid printTask(int id, int code) {\r\n    std::cout << \"Running Task: \" << id << \", Code: \" << code << std::endl;\r\n}\r\n\r\nint main() {\r\n    auto task = std::bind_back(printTask, 42);\r\n    std::thread t([&]() { task(1); });\r\n    t.join();\r\n}\r\n<\/code><\/pre>\n
\u5728\u90e8\u7f72\u4e8e\u7f8e\u56fd\u4e91\u670d\u52a1\u5668<\/strong>\u4e0a\u8fd0\u884c\u8fd9\u7c7b\u7a0b\u5e8f\u65f6\uff0c\u901a\u8fc7\u5408\u7406\u4f7f\u7528 bind_back<\/code> \u7b80\u5316\u5f02\u6b65\u8c03\u7528\uff0c\u53ef\u6709\u6548\u63d0\u5347\u670d\u52a1\u5668\u5e76\u53d1\u54cd\u5e94\u6027\u80fd\u3002<\/p>\n
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2. \u591a\u53c2\u6570\u5c01\u88c5\uff1a\u51fd\u6570\u90e8\u5206\u5e94\u7528\u5b9e\u8df5<\/h3>\n
\u5bf9\u4e8e\u542b\u591a\u4e2a\u53c2\u6570\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u9884\u7ed1\u5b9a\u5c3e\u90e8\u53c2\u6570\uff0c\u52a8\u6001\u4f20\u5165\u524d\u7f6e\u53c2\u6570\uff1a<\/p>\n
int add(int x, int y, int z) { return x + y + z; }\r\n\r\nauto addLater = std::bind_back(add, 3, 4);\r\nstd::cout << addLater(2) << std::endl; \/\/ \u8f93\u51fa 9\uff0c\u76f8\u5f53\u4e8e add(2, 3, 4)\r\n<\/code><\/pre>\n
\u8fd9\u79cd\u65b9\u5f0f\u7279\u522b\u9002\u5408\u9700\u8981\u5728\u4e0d\u540c\u4e0a\u4e0b\u6587\u4e2d\u91cd\u7528\u51fd\u6570\u903b\u8f91\u7684\u670d\u52a1\u7aef\u5f00\u53d1\u3002<\/p>\n
\n
\u4e09\u3001bind_back \u4e0e bind \u7cfb\u5217\u5de5\u5177\u7684\u6bd4\u8f83<\/h2>\n\n\n\n\n\n\n\n
\u7279\u6027<\/th>\nstd::bind<\/th>\nstd::bind_front<\/th>\nstd::bind_back<\/th>\n<\/tr>\n<\/thead>\n
\u7ed1\u5b9a\u4f4d\u7f6e<\/td>\n\u4efb\u610f\uff08\u9700\u5360\u4f4d\u7b26\uff09<\/td>\n\u53c2\u6570\u524d\u90e8<\/td>\n\u53c2\u6570\u540e\u90e8<\/td>\n<\/tr>\n
\u53ef\u8bfb\u6027<\/td>\n\u8f83\u5dee\uff08\u9700\u7406\u89e3\u5360\u4f4d\uff09<\/td>\n\u826f\u597d<\/td>\n\u66f4\u5f3a\uff08\u76f4\u89c2\u5c3e\u90e8\u7ed1\u5b9a\uff09<\/td>\n<\/tr>\n
\u63a8\u8350\u7528\u9014<\/td>\n\u7075\u6d3b\u590d\u6742\u573a\u666f<\/td>\n\u56de\u8c03\u5c01\u88c5\u3001\u524d\u7f6e\u4f20\u53c2<\/td>\n\u5f02\u6b65\u4efb\u52a1\u3001\u540e\u7f6e\u53c2\u6570\u7ed1\u5b9a<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u9009\u62e9\u5408\u9002\u7684\u7ed1\u5b9a\u65b9\u5f0f\u80fd\u663e\u8457\u63d0\u9ad8 C++ \u9879\u76ee\u7684\u4ee3\u7801\u53ef\u7ef4\u62a4\u6027\u4e0e\u53ef\u6269\u5c55\u6027\uff0c\u7279\u522b\u662f\u5728\u670d\u52a1\u5668\u7aef\u903b\u8f91\u7f16\u6392\u4e0e\u4efb\u52a1\u5206\u53d1<\/strong>\u4e2d\u5c24\u4e3a\u5173\u952e\u3002<\/p>\n
\n
\u56db\u3001\u9002\u914d\u73b0\u4ee3\u670d\u52a1\u5668\u5f00\u53d1\u7684\u6700\u4f73\u5b9e\u8df5<\/h2>\n
\u5728\u6784\u5efa\u57fa\u4e8e C++ \u7684\u9ad8\u6027\u80fd\u540e\u7aef\u7cfb\u7edf\u65f6\uff0c\u51fd\u6570\u7ed1\u5b9a\u7684\u4f7f\u7528\u573a\u666f\u5341\u5206\u5e7f\u6cdb\uff0c\u914d\u5408\u7f8e\u56fdVPS<\/strong>\u8d44\u6e90\uff0c\u53ef\u4ee5\u5feb\u901f\u90e8\u7f72\u4ee5\u4e0b\u5e94\u7528\uff1a<\/p>\n