{"id":158767,"date":"2020-09-14T20:18:29","date_gmt":"2020-09-14T12:18:29","guid":{"rendered":"http:\/\/4563.org\/?p=158767"},"modified":"2020-09-14T20:18:29","modified_gmt":"2020-09-14T12:18:29","slug":"%e5%88%9a%e5%bc%80%e5%a7%8b%e5%ad%a6-rust%ef%bc%8c%e8%bf%99%e6%98%af%e4%b8%80%e6%ae%b5%e5%88%9b%e5%bb%ba%e4%b8%80%e4%b8%aa%e5%8e%9f%e5%a7%8b%e6%95%b0%e7%bb%84%e7%9a%84%e4%bb%a3%e7%a0%81%ef%bc%8c","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=158767","title":{"rendered":"\u521a\u5f00\u59cb\u5b66 Rust\uff0c\u8fd9\u662f\u4e00\u6bb5\u521b\u5efa\u4e00\u4e2a\u539f\u59cb\u6570\u7ec4\u7684\u4ee3\u7801\uff0c\u6709\u66f4\u201c\u5b98\u65b9\u201d\u7684\u5b9e\u73b0\u5417\uff1f"},"content":{"rendered":"
\n
\n
\n

\u521a\u5f00\u59cb\u5b66 Rust\uff0c\u8fd9\u662f\u4e00\u6bb5\u521b\u5efa\u4e00\u4e2a\u539f\u59cb\u6570\u7ec4\u7684\u4ee3\u7801\uff0c\u6709\u66f4\u201c\u5b98\u65b9\u201d\u7684\u5b9e\u73b0\u5417\uff1f <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/i> 2<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
\u539f Java \u4ee3\u7801\uff1a
int[] arr = new int[10];
for(int i = 0;i < arr.length;i ++)
arr[i] = i;<\/p>\n

\u6211\u6363\u9f13\u7684 Rust \u4ee3\u7801\uff1a
fn main() {
let mut arr: [i32; 10] = [0; 10];<\/p>\n

for i in 0..arr.len() {
arr[i] = i as i32;
}
}<\/p>\n

\u6709\u4e2a\u7591\u95ee\uff1a
1. Rust \u7684\u539f\u59cb\u6570\u7ec4\u4f3c\u4e4e\u662f\u6ca1\u6709\u201cnew\u201d\u8fd9\u79cd\u7279\u6027\uff0c\u5373\u63d0\u524d\u5f00\u8f9f\u4e00\u4e2a\u7a7a\u95f4\u3002\u5fc5\u987b\u5728\u58f0\u660e\u65f6\u540c\u65f6\u521d\u59cb\u5316\uff1f\u5047\u5982\u6211\u5982\u4e0b\u9762\u8fd9\u6837\u5199\uff1a<\/p>\n

let mut arr: [i32; 10]; \/\/ \u4ec5\u58f0\u660e\u4e00\u4e2a\u6570\u7ec4\uff0c\u672a\u521d\u59cb\u5316<\/p>\n

\u90a3\u4e48 cargo check \u4f1a\u5728 arr[i] = i as i32;\u5904\u63d0\u793a\u6570\u7ec4\u672a\u521d\u59cb\u5316\uff0c\u6709\u6bd4\u6211\u8fd9\u4e2a\u66f4\u597d\u7684\u5199\u6cd5\u5417\uff0c\u5373\u6570\u7ec4\u521d\u59cb\u5316\u65b9\u6cd5\uff1f<\/p>\n

\uff08\u53e6\u5916\u5410\u69fd\u4e0b Rust \u771f\u7684\u5f88\u4e25\u683c\uff0c\u5faa\u73af\u91cc\u7684\u8d4b\u503c\u4ee3\u7801\u5fc5\u987b\u5199 as i32\uff0c\u597d\u50cf\u4e0d\u51c6\u9690\u5f0f\u8f6c\u6362 usize \u5230 i32 \u3002\u3002\uff09 <\/p><\/div>\n

\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (14<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Jirajine <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4e3a\u4ec0\u4e48\u8981\u7528\u539f\u59cb\u6570\u7ec4\u5462\uff0c\u7528 vector \u554a\u3002
    let v1:Vec<i32> = (1..10).collect(); <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : Jirajine <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u81f3\u4e8e\u521d\u59cb\u5316\uff0c\u76f4\u63a5\u58f0\u660e\u7684\u53d8\u91cf\u662f\u5206\u914d\u5728\u6808\u4e0a\u7684\uff0c\u7f16\u8bd1\u65f6\u5c31\u5df2\u786e\u5b9a\uff0c\u6240\u4ee5\u4e0d\u7528\u989d\u5916\u5206\u914d\u7a7a\u95f4\u3002
    \u6240\u6709\u53d8\u91cf\u8bbf\u95ee\u65f6\u5fc5\u987b\u521d\u59cb\u5316\u662f rust \u9759\u6001\u68c0\u67e5\u7684\u8981\u6c42\uff0c\u672a\u521d\u59cb\u5316\u5f53\u7136\u53ef\u4ee5\u8d4b\u503c\uff0c\u53ea\u8981\u8bbf\u95ee\u524d\u8d4b\u503c\u4e86\u5c31\u884c\u3002
    \u4f60\u8fd9\u4e2a\u6570\u7ec4\u4e0d\u80fd\u7684\u539f\u56e0\u662f arr[i]\u672c\u8eab\u5c31\u662f\u4e00\u6b21\u8bbf\u95ee\uff0c\u8c03\u7528 index \u65b9\u6cd5\uff0c\u800c rust \u4e0d\u5141\u8bb8\u8bbf\u95ee\u672a\u521d\u59cb\u5316\u7684\u53d8\u91cf\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @Jirajine \u56e0\u4e3a\u521a\u5b66\uff0c\u60f3\u628a\u4e00\u4e2a Java \u5b9e\u73b0\u7684\u6570\u636e\u7ed3\u6784\u7528 Rust \u91cd\u5199\u4e00\u4e0b\u6765\u7ec3\u4e60\u3002\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : noe132 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    Java \u5728\u4f60 new \u7684\u65f6\u5019\u81ea\u52a8\u5e2e\u4f60\u628a\u6bcf\u4e2a\u503c\u8d4b\u503c\u521d\u59cb\u503c\u4e86\u3002
    https:\/\/stackoverflow.com\/a\/3426854\/6403587 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : CSM <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4f60\u9700\u8981\u533a\u5206\u5f00\u5f15\u7528\u7c7b\u578b\u4e0e\u503c\u7c7b\u578b\u3002<\/p>\n

    > \u90a3\u4e48 cargo check \u4f1a\u5728 arr[i] = i as i32;\u5904\u63d0\u793a\u6570\u7ec4\u672a\u521d\u59cb\u5316<\/p>\n

    \u8fd9\u91cc\u7684\u610f\u601d\u4e0d\u662f\u8bf4\u6570\u7ec4\u7684\u5185\u5bb9\u6ca1\u6709\u521d\u59cb\u5316\uff08\u4e8b\u5b9e\u4e0a\uff0c\u5199\u5165\u6ca1\u6709\u521d\u59cb\u5316\u7684\u5185\u5b58\u662f\u5141\u8bb8\u7684\uff0c\u5e76\u4e14\u662f\u4e2a\u91cd\u8981\u7684\u4f18\u5316\u624b\u6bb5\uff09\uff0c\u800c\u662f\u6307 arr \u8fd9\u4e2a\u53d8\u91cf\u540d\u5b57\u6ca1\u6709\u7ed1\u5b9a\u5230\u5185\u5b58\u4e0a\uff0c <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : CSM <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    > let mut arr: [i32; 10]; \/\/ \u4ec5\u58f0\u660e\u4e00\u4e2a\u6570\u7ec4\uff0c\u672a\u521d\u59cb\u5316<\/p>\n

    \u8fd9\u91cc\u53ea\u662f\u5b9a\u4e49\u4e86\u4e2a\u540d\u5b57\u3002<\/p>\n

    \u5728 Java \u4e2d `int[] arr` \u7684\u610f\u601d\u662f\u5b9a\u4e49\u4e00\u4e2a\u5f15\u7528\uff0c\u4f46\u662f\u56e0\u4e3a\u8fd8\u6ca1\u6709\u88ab\u8d4b\u503c\uff0c\u662f null \u3002
    \u5728 C\/C++ \u4e2d\uff0c`int arr[]` \u540e\u5c31\u5df2\u7ecf\u5728\u6808\u4e3a\u6570\u7ec4\u9884\u7559\u4e86\u7a7a\u95f4\uff0c\u6b64\u65f6\u5df2\u7ecf\u53ef\u4ee5\u5199\u5165\u4e86\uff08\u867d\u7136\u53ef\u4ee5\u8bfb\u53d6\uff0c\u4f46\u4f1a\u662f\u4e00\u4e9b\u6ca1\u7528\u7684\u6570\u636e\uff0c\u5728 C\/C++ \u4e2d\u7ed9\u51fa\u8b66\u544a\uff0c\u800c Rust \u4f1a\u7981\u6b62\u8bfb\u53d6\uff09\uff0c\u4f46\u662f\u5728 Java \u4e2d\u8fd8\u53ea\u662f\u4e2a\u6307\u9488\uff0c\u9700\u8981\u5728\u5806\u4e3a\u6570\u7ec4\u5206\u914d\u4e86\u5185\u5b58\uff08\u5e76\u8d4b\u503c\u7ed9\u8fd9\u4e2a\u6307\u9488\uff09\u540e\u624d\u80fd\u5199\u5165\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @CSM \u597d\u50cf\u66f4\u7406\u89e3\u4e86\u4e00\u4e9b\uff0c\u8c22\u8c22 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : qefrgty <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6ca1\u6709\u3002\u6570\u7ec4\u5fc5\u987b\u5728\u58f0\u660e\u65f6\u76f4\u63a5\u521d\u59cb\u5316\u3002<\/p>\n

    \u5355\u5c31\u4f60\u8fd9\u6bb5\u4ee3\u7801\uff0c\u80fd\u4f18\u5316\u7684\u5730\u65b9\u5c31\u662f\u7b2c\u4e8c\u884c\u4ee3\u7801\u4e2d\u7684 :[i33;0] \u53ef\u4ee5\u5220\u6389\u3002<\/p>\n

    \u5199 rust \u4f60\u5c31\u76f8\u4fe1\u7f16\u8bd1\u5668\u5e76\u6ee1\u8db3\u5b83\u5c31\u5b8c\u4e8b\u513f\u4e86\u3002<\/p>\n

    \u4e0d\u8fc7\u4e0d\u5fc5\u7ea0\u7ed3\u6570\u7ec4\uff0c\u76f4\u63a5 vec \u4e00\u628a\u68ad\uff08\u5927\u96fe\uff09 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @qefrgty : )\u8c22\u8c22 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6211\u6682\u65f6\u89e3\u51b3\u4e86\uff0c\u5927\u4f53\u662f\u7528 Box \u5305\u88c5\u4e86\u4e00\u4e0b\uff1a
    #[derive(Debug)]
    pub struct Array {
    data: Box::<[i32]>,
    size: usize,
    }<\/p>\n

    impl Array {
    pub fn new() -> Array {
    Array {
    data: Box::new([0; 100]),
    size: 0,
    }
    }
    } <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : ldm0 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    “`rust
    use std::mem::{self, MaybeUninit};<\/p>\n

    fn main() {
    let mut arr = unsafe {
    let data: [MaybeUninit<i32>; 10] = MaybeUninit::uninit().assume_init();
    mem::transmute::<_, [i32; 10]>(data)
    };<\/p>\n

    for i in 0..arr.len() {
    arr[i] = i as i32;
    }<\/p>\n

    dbg!(arr);
    }
    “`
    \u53c2\u89c1 <https:\/\/doc.rust-lang.org\/stable\/std\/mem\/union.MaybeUninit.html> <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : RedL0tus <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u8bf4\u53e5\u9898\u5916\u8bdd\uff08<\/p>\n

    \u539f\u59cb\u6570\u7ec4\u5404\u65b9\u9762\u6bd4\u8f83\u63a5\u8fd1 C \u7684\u6570\u7ec4\uff0c\u7528\u7684\u65f6\u5019\u57fa\u672c\u4e0a\u90fd\u662f\u4f7f\u7528\u5b83\u7684 immutable reference \uff1b\u5e94\u7528\u573a\u666f\u9664\u4e86 slice \u6216\u8005\u50cf nom \u90a3\u6837\u641e zero-copy \u6781\u81f4\u6027\u80fd\u4e4b\u5916\u5c31\u6ca1\u591a\u5c11\u4e86\uff08<\/p>\n

    \u5c31\u6211\u81ea\u5df1\u7406\u89e3\u7684\u8bdd\uff0c\u4e00\u822c\u7528 Vec \u662f\u6700\u5408\u9002\u7684\uff08\u53cd\u6b63 Vec \u53ef\u4ee5\u76f4\u63a5 AsRef \u6210 &[T]\uff09\uff0c\u8fd8\u6709\u4e00\u4e2a vec! \u5b8f\u53ef\u4ee5\u7528\uff0c\u5f88\u65b9\u4fbf\u7684\uff08 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : 0gre2019 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @ldm0 \u8001\u54e5\u4f60\u8fd9\u662f\u7ec8\u6781\u89e3\u51b3\u65b9\u6848\uff0c\u6211\u770b\u4e86 Vec \u7684\u6e90\u7801\uff0c\u57fa\u7840\u6570\u636e\u7c7b\u578b\u5c31\u662f MaybeUninit<T>\uff0c\u8c22\u4e86\uff01 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : CSM <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @ldm0 \u662f\u4e0d\u662f transmute \u7684\u592a\u65e9\u4e86\u2026\u2026 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"

    \u521a\u5f00\u59cb\u5b66 Rust\uff0c\u8fd9\u662f\u4e00\u6bb5\u521b\u5efa\u4e00…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/158767"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=158767"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/158767\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=158767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=158767"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=158767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}