{"id":374,"date":"2020-04-02T10:57:56","date_gmt":"2020-04-02T02:57:56","guid":{"rendered":"https:\/\/www.notown.club\/?p=374"},"modified":"2020-04-05T22:54:04","modified_gmt":"2020-04-05T14:54:04","slug":"c%e5%87%bd%e6%95%b0%ef%bc%88%e7%ac%94%e8%ae%b0%e4%ba%8c%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.notown.top\/?p=374","title":{"rendered":"C++\u51fd\u6570\uff08\u7b14\u8bb0\u4e8c\uff09"},"content":{"rendered":"\n

\u4e00\u3001\u5185\u8054\u51fd\u6570<\/strong><\/p>\n\n\n\n

\u5185\u8054\u51fd\u6570\u53ef\u907f\u514d\u51fd\u6570\u8c03\u7528\u7684\u5f00\u9500\uff1a
\u5728\u5927\u591a\u6570\u673a\u5668\u4e0a\uff0c\u4e00\u6b21\u51fd\u6570\u8c03\u7528\u5176\u5b9e\u5305\u542b\u7740\u4e00\u7cfb\u5217\u5de5\u4f5c\uff1a
1\u3001\u8c03\u7528\u524d\u8981\u5148\u4fdd\u5b58\u5bc4\u5b58\u5668\uff0c\u5e76\u5728\u8fd4\u56de\u65f6\u6062\u590d\uff1b
2\u3001\u53ef\u80fd\u9700\u8981\u62f7\u8d1d\u5b9e\u53c2\uff1b
3\u3001\u7a0b\u5e8f\u8f6c\u5411\u4e00\u4e2a\u65b0\u7684\u4f4d\u7f6e\u7ee7\u7eed\u6267\u884c\uff1b<\/p>\n\n\n\n

\u5c06\u51fd\u6570\u6307\u5b9a\u4e3a\u5185\u8054\u51fd\u6570(inline<\/strong>)\uff0c\u901a\u5e38\u5c31\u662f\u5c06\u5b83\u5728\u6bcf\u4e2a\u8c03\u7528\u70b9\u4e0a\u201c\u5185\u8054\u5730\u201d\u5c55\u5f00.
\u4e00\u822c\u6765\u8bf4\uff0c\u5185\u655b\u673a\u5236\u7528\u4e8e\u4f18\u5316\u89c4\u6a21\u8f83\u5c0f\u3001\u6d41\u7a0b\u76f4\u63a5\u3001\u9891\u7e41\u8c03\u7528\u7684\u51fd\u6570<\/strong>\u3002\u5f88\u591a\u7f16\u8bd1\u5668\u90fd\u4e0d\u652f\u6301\u5185\u655b\u9012\u5f52\u51fd\u6570\u3002
\uff08\u5185\u8054\u8bf4\u660e\u53ea\u662f\u5411\u7f16\u8bd1\u5668\u53d1\u51fa\u7684\u4e00\u4e2a\u8bf7\u6c42\uff0c\u7f16\u8bd1\u5668\u53ef\u9009\u62e9\u5ffd\u7565\u8fd9\u4e2a\u8bf7\u6c42\uff09<\/p>\n\n\n\n

\u4e8c\u3001constexpr\u51fd\u6570<\/strong><\/p>\n\n\n\n

constexpr\u51fd\u6570\u662f\u6307\u7528\u4e8e\u5e38\u91cf\u8868\u8fbe\u5f0f\u7684\u51fd\u6570\u3002\u5b9a\u4e49constexpr\u51fd\u6570\u7684\u65b9\u6cd5\u4e0e\u5176\u5b83\u51fd\u6570\u7c7b\u4f3c\uff0c\u4e0d\u8fc7\u8981\u9075\u5faa\u51e0\u9879\u7ea6\u5b9a\uff08constexpr\u51fd\u6570\u88ab\u9690\u5f0f\u5730\u6307\u5b9a\u4e3a\u5185\u8054\u51fd\u6570\uff09\uff1a
1\u3001\u51fd\u6570\u7684\u8fd4\u56de\u7c7b\u578b\u53ca\u6240\u6709\u5f62\u53c2\u7684\u7c7b\u578b\u90fd\u5f97\u662f\u5b57\u9762\u503c\u7c7b\u578b
2\u3001\u51fd\u6570\u4f53\u4e2d\u6709\u4e14\u4ec5\u6709\u4e00\u6761return\u8bed\u53e5\u3002<\/p>\n\n\n\n

constexpr size_t scale(size_t cnt)
 {
     return 8*cnt;
 }<\/pre>\n\n\n\n
\u8c03\u7528\u5982\u4e0a\u7a0b\u5e8f\uff0c\u53ea\u8981\u4f20\u5165\u7684\u53c2\u6570\u662f\u4e00\u4e2a\u5e38\u91cf\u8868\u8fbe\u5f0f\uff0c\u5219\u80fd\u8fd4\u56de\u4e00\u4e2a\u5e38\u91cf\u8868\u8fbe\u5f0f\u3002\u76f8\u53cd\u82e5\u4f20\u5165\u4e00\u4e2a\u53d8\u91cf\uff0c\u5219\u4f1a\u51fa\u9519\u3002<\/p>\n\n\n\n
\u8bf7\u628a\u5185\u8054\u51fd\u6570\u548cconstexpr\u51fd\u6570\u653e\u5728\u5934\u6587\u4ef6\u4e2d\uff01<\/strong>
\u548c\u5176\u5b83\u51fd\u6570\u4e0d\u4e00\u6837\uff0c\u5185\u655b\u51fd\u6570\u548cconstexpr\u51fd\u6570\u53ef\u4ee5\u5728\u7a0b\u5e8f\u4e2d\u591a\u6b21\u5b9a\u4e49\uff0c\u56e0\u4e3a\u7f16\u8bd1\u5668\u60f3\u8981\u5c55\u5f00\u51fd\u6570\u4ec5\u6709\u51fd\u6570\u58f0\u660e\u662f\u4e0d\u591f\u7684\uff0c\u8fd8\u9700\u8981\u51fd\u6570\u7684\u5b9a\u4e49\u3002\u4e0d\u8fc7\uff0c\u5bf9\u4e8e\u67d0\u4e2a\u7ed9\u5b9a\u7684\u5185\u8054\u51fd\u6570\u6216\u8005constexpr\u51fd\u6570\u6765\u8bf4\uff0c\u5b83\u7684\u591a\u4e2a\u5b9a\u4e49\u5fc5\u987b\u4e00\u81f4\u3002\u57fa\u4e8e\u8fd9\u4e2a\u539f\u56e0\uff0c\u5185\u8054\u51fd\u6570\u548cconstexpr\u51fd\u6570\u901a\u5e38\u5b9a\u4e49\u5728\u5934\u6587\u4ef6\u4e2d\u3002 <\/p>\n\n\n\n
\uff08\u8fd9\u91cc\u6709\u4e2a\u94fe\u63a5\u662f\u603b\u7ed3\u5934\u6587\u4ef6\u548c\u6e90\u6587\u4ef6\u5e94\u8be5\u653e\u54ea\u4e9b\u5185\u5bb9\u7684https:\/\/www.cnblogs.com\/fenghuan\/p\/4794514.html<\/a>\uff09<\/p>\n\n\n\n
\u4e09\u3001\u8c03\u8bd5\u5e2e\u52a9<\/strong><\/p>\n\n\n\n
\u7a0b\u5e8f\u53ef\u4ee5\u5305\u542b\u4e00\u4e9b\u7528\u4e8e\u8c03\u8bd5\u7684\u4ee3\u7801\uff0c\u4f46\u662f\u8fd9\u4e9b\u4ee3\u7801\u5e94\u8be5\u53ea\u5728\u5f00\u53d1\u7a0b\u5e8f\u7684\u4f7f\u7528\uff0c\u5f53\u7a0b\u5e8f\u5b8c\u6210\uff0c\u51c6\u5907\u53d1\u5e03\u65f6\uff0c\u5e94\u5c4f\u853d\u6389\u8c03\u8bd5\u4ee3\u7801\u3002\u8fd9\u79cd\u65b9\u6cd5\u7528\u5230\u4e24\u9879\u9884\u5904\u7406\u529f\u80fdassert\u548cNDEBUG\u3002<\/p>\n\n\n\n
assert\u9884\u5904\u7406\u5b8f\uff08\u5728cassert\u5934\u6587\u4ef6\u91cc\uff09<\/strong>
assert\u662f\u4e00\u79cd\u9884\u5904\u7406\u5b8f\uff0c\u6240\u8c13\u7684\u9884\u5904\u7406\u5b8f\uff0c\u5c31\u662f\u4e00\u4e2a\u9884\u5904\u7406\u53d8\u91cf\uff0c\u5b83\u7684\u884c\u4e3a\u6709\u70b9\u7c7b\u4f3c\u5185\u8054\u51fd\u6570\u3002assert\u5b8f\u4f7f\u7528\u4e00\u4e2a\u8868\u8fbe\u5f0f\u4f5c\u4e3a\u5b83\u7684\u6761\u4ef6\uff1b
assert(expr);<\/code>
\u5148\u5bf9expr\u6c42\u503c\uff0c\u5982\u679c\u8868\u8fbe\u5f0f\u4e3a\u5047\uff080\uff09\uff0cassert\u8f93\u51fa\u4fe1\u606f\u5e76\u7ec8\u6b62\u7a0b\u5e8f\u8fd0\u884c\uff1b\u5982\u679c\u8868\u8fbe\u5f0f\u4e3a\u771f\uff08\u975e0\uff09\uff0cassert\u4ec0\u4e48\u90fd\u4e0d\u505a\u3002
assert(word,size() > threshold)<\/code>\/\/\u5f53\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u5c0f\u4e8e\u67d0\u4e2a\u503c\uff0c\u5c31\u4f1a\u7ec8\u6b62\u7a0b\u5e8f\u3002
NDEBUG\u9884\u5904\u7406\u53d8\u91cf<\/strong>
assert\u7684\u884c\u4e3a\u4f9d\u8d56\u4e8e\u4e00\u4e2a\u540d\u4e3aNDEBUG\u7684\u9884\u5904\u7406\u53d8\u91cf\u7684\u72b6\u6001\u3002\u5982\u679c\u5b9a\u4e49\u4e86NDEBUG\uff0c\u5219assert\u4ec0\u4e48\u4e5f\u4e0d\u505a\uff0c\u9ed8\u8ba4\u72b6\u6001\u4e0b\u6ca1\u6709\u5b9a\u4e49NDEBUG\uff0c\u6b64\u65f6assert\u5c06\u6267\u884c\u8fd0\u884c\u65f6\u68c0\u67e5\u3002\u4f46assert\u53ea\u662f\u8c03\u8bd5\u7a0b\u5e8f\u7684\u4e00\u79cd\u8f85\u52a9\u624b\u6bb5\uff0c\u5e76\u4e0d\u80fd\u4ee3\u66ff\u771f\u6b63\u7684\u8fd0\u884c\u65f6\u7684\u903b\u8f91\u68c0\u67e5\uff0c\u4e5f\u4e0d\u80fd\u4ee3\u66ff\u7a0b\u5e8f\u672c\u8eab\u5e94\u8be5\u5305\u542b\u7684\u9519\u8bef\u68c0\u67e5\u3002\u9664\u4e86assert\u5916\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528NDEBUG\u7f16\u5199\u81ea\u5df1\u7684\u6761\u4ef6\u8c03\u8bd5\u4ee3\u7801\u3002<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e00\u3001\u5185\u8054\u51fd\u6570 \u5185\u8054\u51fd\u6570\u53ef\u907f\u514d\u51fd\u6570\u8c03\u7528\u7684\u5f00\u9500\uff1a \u5728\u5927\u591a\u6570\u673a\u5668\u4e0a\uff0c\u4e00\u6b21\u51fd\u6570\u8c03\u7528\u5176\u5b9e\u5305\u542b\u7740\u4e00\u7cfb\u5217\u5de5\u4f5c\uff1a 1\u3001\u8c03\u7528\u524d\u8981…Continue reading C++\u51fd\u6570\uff08\u7b14\u8bb0\u4e8c\uff09<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[11],"tags":[],"class_list":["post-374","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/posts\/374","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.notown.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=374"}],"version-history":[{"count":2,"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/posts\/374\/revisions"}],"predecessor-version":[{"id":426,"href":"https:\/\/www.notown.top\/index.php?rest_route=\/wp\/v2\/posts\/374\/revisions\/426"}],"wp:attachment":[{"href":"https:\/\/www.notown.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.notown.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=374"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.notown.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}