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�l�制牛顿法复杂边界分形图 && ��L(f��ng)��扭�Ӟ��

��山日志 — Sun, 31 Dec 2006 15:58:00 GMT

谨以此图BS自己的懒惰行为！呵呵�Q?月䆾的想法到现在才完成。还好没有拖�?7�q�去^_^�?br />先把囄��和代码给出，明天再把文字补上�?br />

��山日志 2006-12-31 23:58 发表评论

�U�C�~�写的矩阵工具包

��山日志 — Thu, 07 Dec 2006 09:06:00 GMT

同学找我帮忙写的�Q�要求：(x��)
矩阵�怹��Q�纯C�~�写�?br />不能用C++�q�点让我十分郁闷啊^_^....
一共包含如下东西：(x��)

typedef struct _matrix2D matrix2D; //一个结构体�c�d��matrix2D

BOOL initMatrix(matrix2D* pm, int h, int w); //初始化pm为h×w的零矩阵
void delMatrix(matrix2D* pm);  //矩阵的内部数据空间全部是动态分配的�Q�所以退��Z��前一定要删除矩阵
int getData(matrix2D* pm, int x, int y);  //�q�回矩阵pm�Q�坐标�ؓ(f��)x、y的元素�?/span>
void setData(matrix2D* pm, int x,int y, int data);   //��矩阵pm�Q�坐标�ؓ(f��)x、y的元素值置为data
void setMatrix(matrix2D* lhs, matrix2D* rhs);  //删除矩阵lhs原先的��|��q�深层拷贝�ؓ(f��)rhs
matrix2D addMatrix(matrix2D* lhs, matrix2D* rhs);  //矩阵相加�Q�返回一个新的矩�?/span>
matrix2D mulMatrix(matrix2D* lhs, matrix2D* rhs);  //矩阵�怹��Q�返回一个新的矩�?/span>
void printMatrix(matrix2D* pm);  //格式化打印矩阵pm

�q�是一个测试程序，��单相乘两个矩阵：(x��)

#include "matrix2d.h"

int main()
{
    int i,j;
    matrix2D  rhs;
    matrix2D  lhs;
    matrix2D  result;

    initMatrix(&lhs, 11, 10);
    initMatrix(&rhs, 10, 2);

        //lhs矩阵讄��元素�?/span>
    for(i = 0; i<11; i++){
        for(j = 0; j<10; j++){
            setData(&lhs, i, j, 1);
        }
    }
        //rhs矩阵讄��元素�?/span>
    for(i = 0; i<10; i++){
        for(j = 0; j<2; j++){
            setData(&rhs, i, j, i+1);
        }
    }
        //矩阵�怹�
    result = mulMatrix(&lhs, &rhs);
        //打印三个矩阵
    printMatrix(&lhs);
    printMatrix(&rhs);
    printMatrix(&result);
        //不用了，记得释放矩阵�I�间..
    delMatrix(&lhs);
    delMatrix(&rhs);
    delMatrix(&result);
}

�q�里是显�C�结果：(x��)

点击�q�里下蝲完整的源代码和运行程序�?br />

��山日志 2006-12-07 17:06 发表评论

��山日志 — Tue, 05 Dec 2006 06:45:00 GMT

    �q�是严蔚敏《数据结构》配套习(f��n)题册上的题目�Q�将逆�L兰式转换成�L兰式�Q��ƈ提示错误�Q�作为简化，只处�?+-*/"�?~9的数字）�?br />    例如�Q?123*-"转换成�L兰式�?-1*23"
    逆�L兰式"123*-"的表辑ּ��?w��i)如下�?x��)
    所以这个�{换过�E�就是：(x��)已知一个二叉树(w��i)的后栚w��历序列，求先栚w��历序列�?br />    我的��法是根据后栚w��历的序列构造一个表辑ּ��?w��i)，�q�而先栚w��历此�?w��i)获得�L兰式表达式�?br />    定义了两个结构体�Q?br />

struct Exp{
    char  op;
    Item  lhs;
    Item  rhs;
    Exp(){};
    Exp(char _op, Item _lhs, Item _rhs):op(_op), lhs(_lhs), rhs(_rhs){ }
    Exp(const Exp& e):op(e.op), lhs(e.lhs), rhs(e.rhs) { }
};

表示一个表辑ּ��Q�也是表辑ּ��?w��i)上的一个子�?w��i)�?br />

struct Item{
    char  number;
    shared_ptr<Exp> pExp;
    bool isNumber;
    explicit Item():isNumber(true), number('0'), pExp(){    }
    Item(const Item& i):number(i.number), pExp(i.pExp), isNumber(i.isNumber){ }
};

表示一个节点，它可以是一个数字，或者一个表辑ּ��Q�pExp�q�里我��用的�?a >boost�?/a>的智能指针shared_ptr�Q�所以编译的话，需要先安装boost库）�?br />�q�行的结果如图：(x��)

*输入�Ӟ��?e'表示输入�l�束�?br />完整的代码和可执行文件点�?a class="" title="" href="/Files/nj-blog/porland.rar" target="">�q�里下蝲。权当抛砖引玉了�Q�希望有更好��法的同学赐教�?br />

完整的代码：(x��)

��山日志 2006-12-05 14:45 发表评论

��山日志 — Sun, 05 Nov 2006 13:30:00 GMT

转自Dreamer's Blog

      今天在网上无意中发现了苹果电(sh��)脑之父乔布斯在斯坦福大学的演�Ԍ��他在演讲中说了三个关于自��q��故事�Q�我看了之后很有感触。今天把原文和译文都发上来，供大家参考。另�?a target="_blank" tip="">�q�里有YouTube上的视频观看�?a target="_blank" tip="">�q�里有演讲mp3下蝲�?/a>

      Steve Jobs��_(d��)��你得扑և�你爱�?(You've got to find what you love.)。�?br />
      以下是苹果计��机公司与Pixar动画制作室执行长Steve Jobs�?005�q�六�?2日对全体史丹�?j��ng)大学毕业生的演讲内容�?x��)

      今天�Q�有荣幸来到各位从世界上最好的学校之一毕业的毕业典�C�g��。我从来没从大学毕业。说实话�Q�这是我��d��学毕业最�q�的一刅R��今天，我只说三个故事，不谈大道理，三个故事��好。�?br />
      �W�一个故事，是关于�h生中的点�Ҏ(gu��)��滴怎么串连在一赗��?br />
      我在里�d学院�Q�Reed college�Q�待了六个月��办休学了。到我退学前�Q�一�׃��学了十八个月。那么，我�ؓ(f��)什么休学？

      �q�得从我出生前讲赗��我的亲生母亲当时是个研�I�生�Q�年��L��婚妈妈，她决定让别�h收养我。她强烈觉得应该让有大学毕业的�h收养我，所以我出生�Ӟ��她就准备让我被一对律师夫妇收充R��但是这对夫��d��了最后一��d��(zh��n)�了�Q�他们想收养奛_��。所以在�{�待收养名单上的一对夫妻，我的�ȝ��母，在一天半夜里接到一通电(sh��)话，问他们「有一名意外出生的男孩�Q�你们要认养他吗�Q�」而他们的回答是「当然要」。后来，我的生母发现�Q�我现在的妈妈从来没有大学毕业，我现在的爸爸则连高中毕业也没有。她拒绝在认��L��件上做最后签字。直到几个月后，我的�ȝ��母同意将来一定会(x��)让我上大学，�Ҏ(gu��)��软化态度。�?br />
      十七�q�后�Q�我上大学了。但是当时我无知选了一所学费几乎跟史丹佛(j��ng)一栯��的大学，我那工�h阶��的父母所有积蓄都花在我的学费上。六个月后，我看不出念这个书的�h(hu��n)��g��在。那时候，我不知道�q�辈子要�q�什么，也不知道念大学能�Ҏ(gu��)��有什么帮助，而且我�ؓ(f��)了念�q�个书，花光了我父母�q�辈子的所有积蓄，所以我军_��休学�Q�相信船到桥头自然直。当时这个决定看来相当可怕，可是现在看来�Q�那是我�q�辈子做�q�最好的军_��之一。当我休学之后，我再也不用上我没兴趣的必修课�Q�把旉��拿去听那些我有兴��的课。�?br />
      �q�一点也不浪漫。我没有宿舍�Q�所以我睡在友�h安��的地板上�Q�靠着回收可乐�I�罐的五先��o(h��)退费买吃的�Q�每个星期天晚上得走七里的�\�l�过大半个镇��d��度教的Hare Krishna��庙吃顿好料。我喜欢Hare Krishna��庙的好料。追��L��的好奇与直觉�Q�我所驻��的大部分事物�Q�后来看来都成了无�h(hu��n)之宝。�D例来��_(d��)��(x��)

      当时里�d学院有着大概是全国最好的书法指导。在整个校园内的每一张�v报上�Q�每个抽屉的标签上，都是��丽的手写字。因为我休学了，可以不照正常选课�E�序来，所以我跑去学书法。我学了serif与san serif字体�Q�学到在不同字母�l�合间变更字间距�Q�学到活版印刷伟大的地方。书法的��好、历史感与艺术感是科学所无法捕捉的，我觉得那很迷人。�?br />
      我没预期�q�学的这些东西能在我生活中�v些什么实际作用，不过十年后，当我在设计第一台麦金塔�Ӟ��我想起了当时所学的东西�Q�所以把�q�些东西都设计进了麦金塔里，�q�是�W�一台能印刷出漂亮东西的计算机。如果我没沉��Z��那样一门课里，麦金塔可能就不会(x��)有多重字体跟变间距字体了。又因�ؓ(f��)Windows抄袭了麦金塔的��用方式，如果当年我没�q�样做，大概世界上所有的个�h计算机都不会(x��)有这些东西，��C��出现在我们看到的漂亮的字来了。当�?d��ng)��当我�q�在大学里时�Q�不可能把这些点�Ҏ(gu��)��滴预先串在一��P��但是�q�在十年后回��，��显得非常清楚。�?br />
      我再说一�ơ，你不能预先把点点滴滴串在一��P��唯有未来回顾�Ӟ��你才�?x��)明白那些点��?gu��)��滴是如何串在一��L(f��ng)��。所以你得相信，你现在所体会(x��)的东西，��来多少�?x��)连接在一块。你得信��L��个东西，直觉也好�Q�命�q�也好，生命也好�Q�或者业力。这�U�作法从来没让我失望�Q�也让我的�h生整个不同�v来。�?/span>

      我的�W�二个故事，有关�׃��失去。�?br />
      我好�q�－�q�轻时就发现自己爱做什么事。我二十岁时�Q�跟Steve Wozniak在我爸妈的�R库里开始了�Ҏ(gu��)��计算机的事业。我们拼命工作，�Ҏ(gu��)��计算机在十年间从一间�R库里的两个小伙子扩展成了一家员工超�q�四千�h、市价二十亿��金的公司，在那之前一�q�推��Z��我们最��的作品�Q�麦金塔�Q�而我才刚�q�入人生的第三十个年��_(d��)��然后被炒鱉K��。要怎么让自己创办的公司炒自己鱿��|��好吧�Q�当�Ҏ(gu��)��计算机成长后�Q�我请了一个我以�ؓ(f��)他在�l�营公司上很有才�q�的家伙来，他在头几�q�也��实�q�得不错。可是我们对未来的愿景不同，最后只好分道扬镻I��董事�?x��)站在他那边�Q�炒了我鱉K��Q�公开把我请了出去。曾�l�是我整个成�q�生�z�重心的东西不见了，令我不知所措。�?br />
      有几个月�Q�我实在不知道要�q�什么好。我觉得我��o(h��)企业界的前辈们失望－我把他们交给我的接力��弄丢了。我见了创办HP的David Packard跟创办Intel的Bob Noyce�Q�跟他们说我很抱歉把事情搞砸得很厉害了。我成了公众的非常负面示范，我甚��x��要离开��谷。但是渐渐的�Q�我发现�Q�我�q�是喜爱着我做�q�的事情�Q�在�Ҏ(gu��)��的日子经历的事�g没有丝毫改变我爱做的事。我被否定了�Q�可是我�q�是爱做那些事情�Q�所以我军_��从头来过。�?br />
      当时我没发现�Q�但是现在看来，被苹果计��机开除，是我所�l�历�q�最好的事情。成功的沉重被从头来�q�的��L��所取代�Q�每件事情都不那么确定，让我自由�q�入�q�辈子最有创意的�q�代。�?br />
      接下来五�q�_(d��)��我开了一家叫做NeXT的公司，又开一家叫做Pixar的公司，也跟后来的老婆谈�v了恋爱。Pixar接着制作了世界上�W�一部全计算机动�ȝ��(sh��)影，玩具��d��员，现在是世界上最成功的动��d��作公司。然后，�Ҏ(gu��)��计算��Z��下了NeXT�Q�我回到了苹果，我们在NeXT发展的技术成了苹果计��机后来复兴的核心。我也有了个��妙的家庭。�?br />
      我很��定�Q�如果当�q�苹果计��机没开除我�Q�就不会(x��)发生�q�些事情。这帖药很苦口，可是我想�Ҏ(gu��)��计算��个病人需要这帖药�?span style="COLOR: red">有时候，人生�?x��)用砖头打你的头。不要��׃��心。我��信�Q�我爱我所做的事情�Q�这��是�q�些�q�来让我�l�箋��C��ȝ��唯一理由。你得找��Z��q��Q�工作上是如此，�Ҏ(gu��)��Z��是如此。你的工作将填满你的一大块人生�Q�唯一获得真正满��的方法就是做你相信是伟大的工作，而唯一做伟大工作的�Ҏ(gu��)��是爱你所做的事。如果你�q�没扑ֈ��q�些事，�l�箋找，别停��ѝ��尽你全心全力，你知道你一定会(x��)扑ֈ�。而且�Q�如同�Q何伟大的关系�Q�事情只�?x��)随着旉��愈来愈好。所以，在你扑ֈ�之前�Q��l�找�Q�别停顿。�?/span>

      我的�W�三个故事，关于��M��。�?br />
      当我十七岁时�Q�我��d��一则格�a��Q�好像是「把每一天都当成生命中的最后一天，你就�?x��)轻松自在。」这�Ҏ(gu��)��影响��p��Q�在�q�去33�q�里�Q�我每天早上都会(x��)照镜子，自问�Q�「如果今天是此生最后一日，我今天要�q�些什么？」每当我�q�箋太多天都得到一个「没事做」的�{�案�Ӟ��我就知道我必��L��所变革了。�?br />
      提醒自己快死了，是我在�h生中下重大决定时�Q�所用过最重要的工兗��因为几乎每件事�Q�所有外界期望、所有名誉、所有对困窘或失败的恐惧�Q�在面对��M��Ӟ��都消�׃��Q�只有最重要的东西才�?x��)留下。提醒自己快��M��Q�是我所知避免掉入自己有东西要失��M��的陷阱里最好的�Ҏ(gu��)��。�h生不带来�Q�死不带去，没什么道理不��心而�ؓ(f��)。�?br />
      一�q�前�Q�我被诊断出癌症。我在早上七点半作断层扫描，在胰脏清楚出��C��个肿瘤，我连胰脏是什么都不知道。医生告诉我�Q�那几乎可以��定是一�U�不��M��症，我大概活不到三到六个月了。医生徏议我回家�Q�好好跟亲�h们聚一聚，�q�是�ȝ��对��(f��)�l�病人的标准��。那代表你得试着在几个月内把你将来十�q�想跟小孩讲的话讲完。那代表你得把每件事情搞定，家�h才会(x��)��量��L��。那代表你得跟�h说再见了。�?br />
      我整天想着那个诊断�l�果�Q�那天晚上做了一�ơ切片，从喉咙��入一个内视镜�Q�从胃进肠子�Q�插了根针进胰脏�Q�取了一些肿瘤细�?y��u)出来。我打了镇静剂，不醒��Z��Q�但是我老婆在场。她后来跟我��_(d��)��当医生们用显微镜看过那些�l�胞(y��u)后，他们都哭了，因�ؓ(f��)那是非常��见的一�U�胰脏癌�Q�可以用手术��d��。所以我接受了手术，康复了。�?br />
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      没有人想歅R��即佉K��些想上天堂的人，也想�zȝ��上天堂。但是死亡是我们共有的目的地�Q�没有�h逃得�q�。这是注定的�Q�因为死亡简直就是生命中最��的发明�Q�是生命变化的媒介，送走老�h们，�l�新生代留下�I�间。现在你们是新生代，但是不久的将来，你们也会(x��)逐渐变老，被送出人生的舞台。抱歉讲得这么戏剧化�Q�但是这是真的。�?br />
      你们的时间有限，所以不要浪�Ҏ(gu��)��间活在别人的生活里。不要被信条所惑－盲从信条��是�z�d��别�h思考结果里。不要让别�h的意见��没了你内在的心声。最重要的，拥有跟随内心与直觉的勇气�Q�你的内心与直觉多少已经知道你真正想要成��Z��么样的�h。�Q何其它事物都是次要的。�?/span>

      在我�q�轻�Ӟ��有本��奇的杂志叫做Whole Earth Catalog�Q�当�q�我们很�q��本杂志。那是一位住在离�q�不�q�的Menlo Park的Stewart Brand发行的，他把杂志办得很有诗意。那�?960�q�代末期�Q�个��机跟桌上出版还没发明，所有内定w��是打字机、剪刀跟拍立得相机做出来的。杂志内�Ҏ(gu��)��点像印在�U怸�的Google�Q�在Google出现之前35�q�就有了�Q�理惛_��Q�充满新奇工具与��奇的注记。�?br />
      Stewart跟他的出版团队出了好几期Whole Earth Catalog�Q�然后出了停刊号。当时是1970�q�代中期�Q�我正是你们现在�q�个�q�龄的时候。在停刊��L(f��ng)��底�Q�有张早晨乡间小路的照片�Q�那�U�你�ȝ��山时�?x��)经�q�的乡间��\。在照片下有行小字：(x��)
      求知若饥�Q�虚心若愚。�?/span>

      那是他们亲笔写下的告别讯息，我��L��以此自许。当你们毕业�Q�展开新生�z�，我也以此期许你们。�?br />
      求知若饥�Q�虚心若愚。�?br />
      非常谢谢大家�?

原文�Q?/strong>

Stanford Report, June 14, 2005

'You've got to find what you love,' Jobs says

This is the text of the Commencement address by Steve Jobs, CEO of Apple Computer and of Pixar Animation Studios, delivered on June 12, 2005.

I am honored to be with you today at your commencement from one of the finest universities in the world. I never graduated from college. Truth be told, this is the closest I've ever gotten to a college graduation. Today I want to tell you three stories from my life. That's it. No big deal. Just three stories.

The first story is about connecting the dots.

I dropped out of Reed College after the first 6 months, but then stayed around as a drop-in for another 18 months or so before I really quit. So why did I drop out?

It started before I was born. My biological mother was a young, unwed college graduate student, and she decided to put me up for adoption. She felt very strongly that I should be adopted by college graduates, so everything was all set for me to be adopted at birth by a lawyer and his wife. Except that when I popped out they decided at the last minute that they really wanted a girl. So my parents, who were on a waiting list, got a call in the middle of the night asking: "We have an unexpected baby boy; do you want him?" They said: "Of course." My biological mother later found out that my mother had never graduated from college and that my father had never graduated from high school. She refused to sign the final adoption papers. She only relented a few months later when my parents promised that I would someday go to college.

And 17 years later I did go to college. But I naively chose a college that was almost as expensive as Stanford, and all of my working-class parents' savings were being spent on my college tuition. After six months, I couldn't see the value in it. I had no idea what I wanted to do with my life and no idea how college was going to help me figure it out. And here I was spending all of the money my parents had saved their entire life. So I decided to drop out and trust that it would all work out OK. It was pretty scary at the time, but looking back it was one of the best decisions I ever made. The minute I dropped out I could stop taking the required classes that didn't interest me, and begin dropping in on the ones that looked interesting.

It wasn't all romantic. I didn't have a dorm room, so I slept on the floor in friends' rooms, I returned coke bottles for the 5?? deposits to buy food with, and I would walk the 7 miles across town every Sunday night to get one good meal a week at the Hare Krishna temple. I loved it. And much of what I stumbled into by following my curiosity and intuition turned out to be priceless later on. Let me give you one example:

Reed College at that time offered perhaps the best calligraphy instruction in the country. Throughout the campus every poster, every label on every drawer, was beautifully hand calligraphed. Because I had dropped out and didn't have to take the normal classes, I decided to take a calligraphy class to learn how to do this. I learned about serif and san serif typefaces, about varying the amount of space between different letter combinations, about what makes great typography great. It was beautiful, historical, artistically subtle in a way that science can't capture, and I found it fascinating.

None of this had even a hope of any practical application in my life. But ten years later, when we were designing the first Macintosh computer, it all came back to me. And we designed it all into the Mac. It was the first computer with beautiful typography. If I had never dropped in on that single course in college, the Mac would have never had multiple typefaces or proportionally spaced fonts. And since Windows just copied the Mac, its likely that no personal computer would have them. If I had never dropped out, I would have never dropped in on this calligraphy class, and personal computers might not have the wonderful typography that they do. Of course it was impossible to connect the dots looking forward when I was in college. But it was very, very clear looking backwards ten years later.

Again, you can't connect the dots looking forward; you can only connect them looking backwards. So you have to trust that the dots will somehow connect in your future. You have to trust in something - your gut, destiny, life, karma, whatever. This approach has never let me down, and it has made all the difference in my life.

My second story is about love and loss.

I was lucky - I found what I loved to do early in life. Woz and I started Apple in my parents garage when I was 20. We worked hard, and in 10 years Apple had grown from just the two of us in a garage into a $2 billion company with over 4000 employees. We had just released our finest creation - the Macintosh - a year earlier, and I had just turned 30. And then I got fired. How can you get fired from a company you started? Well, as Apple grew we hired someone who I thought was very talented to run the company with me, and for the first year or so things went well. But then our visions of the future began to diverge and eventually we had a falling out. When we did, our Board of Directors sided with him. So at 30 I was out. And very publicly out. What had been the focus of my entire adult life was gone, and it was devastating.

I really didn't know what to do for a few months. I felt that I had let the previous generation of entrepreneurs down - that I had dropped the baton as it was being passed to me. I met with David Packard and Bob Noyce and tried to apologize for screwing up so badly. I was a very public failure, and I even thought about running away from the valley. But something slowly began to dawn on me - I still loved what I did. The turn of events at Apple had not changed that one bit. I had been rejected, but I was still in love. And so I decided to start over.

I didn't see it then, but it turned out that getting fired from Apple was the best thing that could have ever happened to me. The heaviness of being successful was replaced by the lightness of being a beginner again, less sure about everything. It freed me to enter one of the most creative periods of my life.

During the next five years, I started a company named NeXT, another company named Pixar, and fell in love with an amazing woman who would become my wife. Pixar went on to create the worlds first computer animated feature film, Toy Story, and is now the most successful animation studio in the world. In a remarkable turn of events, Apple bought NeXT, I retuned to Apple, and the technology we developed at NeXT is at the heart of Apple's current renaissance. And Laurene and I have a wonderful family together.

I'm pretty sure none of this would have happened if I hadn't been fired from Apple. It was awful tasting medicine, but I guess the patient needed it. Sometimes life hits you in the head with a brick. Don't lose faith. I'm convinced that the only thing that kept me going was that I loved what I did. You've got to find what you love. And that is as true for your work as it is for your lovers. Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do. If you haven't found it yet, keep looking. Don't settle. As with all matters of the heart, you'll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it. Don't settle.

My third story is about death.

When I was 17, I read a quote that went something like: "If you live each day as if it was your last, someday you'll most certainly be right." It made an impression on me, and since then, for the past 33 years, I have looked in the mirror every morning and asked myself: "If today were the last day of my life, would I want to do what I am about to do today?" And whenever the answer has been "No" for too many days in a row, I know I need to change something.

Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life. Because almost everything - all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart.

About a year ago I was diagnosed with cancer. I had a scan at 7:30 in the morning, and it clearly showed a tumor on my pancreas. I didn't even know what a pancreas was. The doctors told me this was almost certainly a type of cancer that is incurable, and that I should expect to live no longer than three to six months. My doctor advised me to go home and get my affairs in order, which is doctor's code for prepare to die. It means to try to tell your kids everything you thought you'd have the next 10 years to tell them in just a few months. It means to make sure everything is buttoned up so that it will be as easy as possible for your family. It means to say your goodbyes.

I lived with that diagnosis all day. Later that evening I had a biopsy, where they stuck an endoscope down my throat, through my stomach and into my intestines, put a needle into my pancreas and got a few cells from the tumor. I was sedated, but my wife, who was there, told me that when they viewed the cells under a microscope the doctors started crying because it turned out to be a very rare form of pancreatic cancer that is curable with surgery. I had the surgery and I'm fine now.

This was the closest I've been to facing death, and I hope its the closest I get for a few more decades. Having lived through it, I can now say this to you with a bit more certainty than when death was a useful but purely intellectual concept:

No one wants to die. Even people who want to go to heaven don't want to die to get there. And yet death is the destination we all share. No one has ever escaped it. And that is as it should be, because Death is very likely the single best invention of Life. It is Life's change agent. It clears out the old to make way for the new. Right now the new is you, but someday not too long from now, you will gradually become the old and be cleared away. Sorry to be so dramatic, but it is quite true.

Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma - which is living with the results of other people's thinking. Don't let the noise of other's opinions drown out your own inner voice. And most important,  have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.

When I was young, there was an amazing publication called The Whole Earth Catalog, which was one of the bibles of my generation. It was created by a fellow named Stewart Brand not far from here in Menlo Park, and he brought it to life with his poetic touch. This was in the late 1960's, before personal computers and desktop publishing, so it was all made with typewriters, scissors, and polaroid cameras. It was sort of like Google in paperback form, 35 years before Google came along: it was idealistic, and overflowing with neat tools and great notions.

Stewart and his team put out several issues of The Whole Earth Catalog, and then when it had run its course, they put out a final issue. It was the mid-1970s, and I was your age. On the back cover of their final issue was a photograph of an early morning country road, the kind you might find yourself hitchhiking on if you were so adventurous. Beneath it were the words: "Stay Hungry. Stay Foolish." It was their farewell message as they signed off. Stay Hungry. Stay Foolish. And I have always wished that for myself. And now, as you graduate to begin anew, I wish that for you.

Stay Hungry. Stay Foolish.

Thank you all very much.

��山日志 2006-11-05 21:30 发表评论

��山日志 — Thu, 02 Nov 2006 17:10:00 GMT
    孟岩在自��q��blog�?a title="提到�? >提到�?/a> Scott Meyers在Artima.com的C++ Source栏目中发表的一�?×5的系列。其中最后一��是Scott Meyers�?a title="五个最重要的C++Aha�Q�时�? >五个最重要的C++Aha�Q�时�?/a> �Q�孟岩提�C�大家关注最后一个。如果关注过Scott Meyers和他的Effectiv�p�d��的话�Q�对他前四个Aha�Q�时��d��该都已经熟识了�?br />
    �q�里仅翻译第五个�Q?br />
明白Boost�?span style="FONT-STYLE: italic">shared_ptr�?span style="FONT-STYLE: italic">deleter是如何工作的�Q?004
Boost的引用计数智能指针shared_ptr有一个有��的�Ҏ(gu��)��，你可以传入一个函数或者一个函��C��Q��ƈ且当�?br />用计��Cؓ(f��)零时�Q�它�?x��)对指向的对象调用这个deleter。让��U�的是，�q�看��h��很��^凡，但是��L(f��ng)��q�段代码�Q?br />
template<typename  T>
class  shared_ptr {
public:
    template<typename U, typename D>
    explicit  shared_ptr(U* ptr, D deleter);

};

要注意的是在析构的期间shared_ptr必须为类型�ؓ(f��)D的deleter做些安排�Q�以��保它的调用�Q�然而shared_ptr�q�不知道�c�d��D到底是什么。此对象不能包含�c�d��为D的数据成员，当然也不能有一个指向类型�ؓ(f��)D的对象的指针�Q�因为当对象成员数据声明的时候对于D好不知情。那么shared_ptr对象如何在构造期deleter被传入时保存它的�t�迹�Q��ƈ且在�E�后的析构期使用它的呐？更一般的说法�Q�在一个对象的构造期间构造函数如何获得未知类型的信息�Q��ƈ把类型的信息传给此对象，而对象不能保存关于此�c�d��M��提示�?br />
�{�案很简单：(x��)此对象包含一个已知类型的基类指针�Q�Boost��它叫做 sp_counted_base �Q�，指向一个已�l�构造实例化的模板，此模板��承自前面的基�c�，�q��用D作�ؓ(f��)实例化参敎ͼ�Boost使用模板 sp_counted_impl_p �?sp_counted_impl_pd �Q�，使用一个在基类里声明，�l�承�c�M��定义的虚函数来调�?deleter �Q�Boost使用 dispose �Q�。稍微简化了�Q�它看�v来像下面�q�样�Q?br />
它是很明昄��Q�只要你看过它一�ơ。但是只要你看过它一�ơ，你就�?x��)体会(x��)到它可以被用到很多�U�类的地方，它打开了模板设计的新视野，模板化类使用相对较少的模板参敎ͼ�shared_ptr 只是其中一个）可以引用不受数量限制的当前不知名�c�d��的信息。当我意识到我接�q�的东西�Q�我不能��止地露��赏的�W�容�q�摇晃我的脑袋�?br />

��山日志 2006-11-03 01:10 发表评论

Message Crack Wizard for Win32 SDK Developer

��山日志 — Wed, 01 Nov 2006 16:00:00 GMT
本文译自codeproject.com�Q�原文链接与工具�?qi��ng)其源代码下载点�?a class="" title="" target="_blank">�q�里�?br />�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q�－�Q?br /> 导引�Q�WINDOWSX.H头文件简化Win32 SDK�~�程

许多的新手或者调试程序员在编写C(j��)/C++的Windows API�E�序旉��要面对像意大利面一��L(f��ng)��switch...case代码块。当你需要加入一个消息处理到你的�H�口处理�q�程中时�Q�在些代码块中查找例如：(x��)WM_COMMAND�?span style="COLOR: rgb(255,0,0)">WM_CHAR�Q�是相当让�h恐惧的事情�?br />
早在Windows 3.1时代的Windows软�g开发工具包和C/C++7.0�~�译器就附带一个包含一千多行W(xu��)indows处理代码的头文�g。这个头文�g�?span style="FONT-STYLE: italic">�Q�它包含
了许多有用的宏。微软的对这个头文�g的介�l�如下：(x��)

对C�E�序做更严格的类型检查的STRICT宏�?
一些简化Windows�~�程的通用操作的宏�?
一些简化与Windows控�g交流的控件宏�?
消息分流器（一�U�方便，��M��q�且�c�d��安全的处理消息的�Ҏ(gu��)��Q�以�?qi��ng)它们在Windows环境下的参数和返回倹{�?

在Message Cracker Wizard被设计出��C��前，我就从��用这些的宏中获得了效率。如果你�?span style="FONT-STYLE: italic">Windows.h的简单描�q�感兴趣�Q�你可以参见MS知识库的文章#8356 �?br />
好了�Q�让我们来介�l�消息分��器的便利，以及(qi��ng)�Q��ؓ(f��)什么这里发布的工具可以你编写代码的效率�?br />
当你在编写Win32 SDK�E�序�Ӟ��你处理窗口消息通过一个窗口函敎ͼ�通常命名�?span style="COLOR: rgb(255,0,0)">WndProc。在Windows C �E�序中常见的是窗口函数通过关键�?span style="COLOR: rgb(51,51,255)">switch和分支标�{?span style="COLOR: rgb(51,51,255)">case处理所有你需要处理的消息�?br />
可以料想的是我们通常需要在�ȝ��口中处理WM_COMMAND�Q?/span>WM_KEYUP�Q?/span>WM_CLOSE�?/span>WM_DESTROY消息。理��Z��我们�?x��)把�H�口函数写成�q�样�Q?br />
LRESULT CALLBACK MainWndProc (HWND hwnd, UINT msg,   WPARAM wParam, LPARAM lParam)
{
  switch(msg)
  {
    case WM_COMMAND:
    //
    break;

    case WM_KEYUP:
    //
    break;

    case WM_CLOSE:
    //
    break;

    case WM_DESTROY:
    //
    break;

    default:
       return DefWindowProc(hwnd, msg, wParam, lParam);
  }
}
�q�是自Windows 1.0时代以来处理Windows消息使用最多的�Q�确实地�Q�它工作。但是问题是当你开始向你程序中加入更多复杂的特性，例如 MDI�Q�OLE�Q�通用控�g�Q�等�{�，你会(x��)获得一个行��C��千记的窗口函数。你开始反复��用PageDn和PageUp键蟩跃，来寻找你需要修改的消息�?br />
�q�是使用消息分流器的�W�一个好处：(x��)它们提供了处理函数来��?span style="COLOR: rgb(51,51,255)">case标签意大利面�Q�就像MFC做的那样�?br />
�W�二个好处是正确的参数规范化了你的处理函数的使用。你可以��单地使用switch(id)来替�?/span>switch(LOWORD(wparam))�Q�因��Z��?span style="COLOR: rgb(204,0,0)">id作�ؓ(f��)一个“分��器”的参数传递给消息函数�Ӟ��{�同�?span style="COLOR: rgb(204,0,0)">LOWORD(wparam)�?br />
消息处理�?span style="COLOR: rgb(204,0,0)">HANDLE_MSG定义�?span style="FONT-STYLE: italic">windows.h中，如下�Q?/span>
#define HANDLE_MSG(hwnd, message, fn) \
    case (message) : return HANDLE_##message((hwnd), (wParam), (lParam), (fn))

如你从上面宏定义中可以想到的是，��你的代码�{换成“消息分��器”版本，你必��L��持分��宏�Q?span style="COLOR: rgb(204,0,0)">HANDLE_MSG�Q��ƈ且��用函数来处理消息。现在将HANDLE_MSG宏加入到�H�口函数中来。这个宏需要三个参敎ͼ�(x��)一个窗口句�?hwnd)�Q�你要处理的消息(WM_xxxx)�Q�以�?qi��ng)你用来处理此消息的函数。�ؓ(f��)了更好的说明�Q�我把之前的�H�口函数替换成下面的消息分流版：(x��)
LRESULT CALLBACK MainWndProc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
  switch(msg)
  {
    HANDLE_MSG (hwnd, WM_COMMAND, OnCommand);
    HANDLE_MSG (hwnd, WM_KEYUP,   OnKeyup);
    HANDLE_MSG (hwnd, WM_CLOSE,   OnClose);
    HANDLE_MSG (hwnd, WM_DESTROY, OnDestroy);
    default:
        return DefWindowProc(hwnd, msg, wParam, lParam);
  }
}

哇！�q�是更好的，��z�的�q�且�Ҏ(gu��)��控制的窗口函数。现在你需要定义的的消息处理函�?OnKeyUp, OnClose�?span style="COLOR: rgb(204,0,0)">OnDestroy)。更加便利的是你可以使用Visual Studio IDE跛_��你消息处理函敎ͼ�(x��)

问题是每一�ơ你增加一个消息处理你都必��L��?span style="FONT-STYLE: italic">WINDOWS.H里的定义�Q�以匚w��你的消息处理函数的参数类型，因�ؓ(f��)你不能随意的使用参数�c�d��Q�处理函数的格式是清楚定义的。在头文件中反复的查找是单调乏味的�Q务，且容易出错。消息分��器Wizard工具来搭救你了：(x��)它允�怽��_�脓(chu��ng)��M��你需要的消息处理的正��的参数。如果你刚刚开始编写代码，它还可以生成一个窗口模板或者对话框函数作�ؓ(f��)你处理窗口消息的开始�?br />
Message forwarding宏：(x��)另一个WINDOWS.H特色

头文�?span style="FONT-STYLE: italic">windowsx.h的另一个特色大�U�是message forwarding。它用来“拆除”消息处理函数的参数为有效的WPARAM�?span style="COLOR: rgb(204,0,0)">LPARAM的�?/span>�Q�以调用诸如PostMessage�Q?span style="COLOR: rgb(204,0,0)">SendMessage�Q?span style="COLOR: rgb(204,0,0)">CallWindowProc�{�等�Q�此�cȝ��函数�?br />

假设你你希望使用SendMessage函数来发�?span style="COLOR: rgb(204,0,0)">WM_COMMAND消息�l�父�H�口�Q�通过以一个通知�?span style="COLOR: rgb(204,0,0)">BN_DBLCLK来“模拟”双��M��个命名�ؓ(f��)IDC_USERCTL的控件。你通常�?x��)这样写�Q?br />
SendMessage (hwndParent, WM_COMMAND,
    MAKEWPARAM(IDC_USERCTL, BN_DBLCLK),
     (LPARAM)GetDlgItem(hwnd, ID_USERCTL));

�q�是一个复杂的的语法：(x��)函数SendMessage期望WPARAM参数的底字节是控件的ID�Q�高字节是通知码；�q�且我们要通过API函数GetDlgItem获得控�g句柄�Q�传�l?/span>LPARAM参数�?br />
上面的代码可以用Windows.h的message forwarding宏替换，FORWARD_WM_XXXX。对于每一个消息，forwarding宏都使用和消息分��器生成的消息处理函数相同的“捆扎”参敎ͼ�增加你希望调用的函数�q�且传给它“拆除”后�?span style="COLOR: rgb(204,0,0)">LPARAM/WPARAMs。例如，消息分流器Wizard�?span style="COLOR: rgb(204,0,0)">WM_COMMAND消息和窗口IDmyWnd生成如下的函数原型：(x��)
void myWnd_OnCommand (HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
好了�Q�这些分��器参数也同栯��用于forwarding�?-因此�Q�如你所期望的，我们之前调用SendMessage函数时展现的混�ؕ可以减少了：(x��)
FORWARD_WM_COMMAND (hwndParent, IDC_USERCTL,
GetDlgItem(hwnd, ID_USERCTL), BN_DBLCLK, SendMessage);
�q�种方式非常��便，�q�且可以为所有消息分��器Wizard支持的消息工作�?br />

使用消息分流Wizard工具

当你�q�行消息分流器Wizard�Ӟ��你可以看��C��面的�H�口�Q?br />

Wizard在左上角的列表框里�ؓ(f��)你提供了WINDOWS.H里有的消息处理，你可以点��M��个或者多个消息。你可以在窗口ID�~�辑框里指定一个窗口标识，以指定你要发送消息的
�H�口。通用的ID�?MainWnd �Q�About (关于对话框）�Q�等�{�。这个标识会(x��)体现在消息处理函��C��Q�和 HANDLE_MSG 宏中�Q�如果你刚刚开始编写代码，它还可以体现在窗
�?对话框处理函��C��。�?Make Window Procedure”选定框的作用是：(x��)允许你通过选定的消息分��器的宏来生成一个窗�?对话框函数的框架。以�q�种方式来开始一
个Windows API��目�Q�你可以清晰的编写和�l�织你的代码�Q�当然还有，避免错误。在�H�口下面的两个编辑框�?x��)包含分��器的宏和处理所选消息的函数�Q�只是原型）生成的代
码。要注意的是�Q�当你选择�?span style="FONT-WEIGHT: bold">Make Window Procedure”时�H�口处理函数的模板代码不出现在这里：(x��)它仅体现在你点击了�?span style="FONT-WEIGHT: bold">Copy Macro”时复制��C��的C++�~�辑器中
的代码里�?br />
让我们通过例子来快速的��览消息分流器Wizard工具的特性。记住你必须先通过#include ��头文�g包含��C��.C/.CPP文�g中�?br />
快速浏览消息分��器Wizard�Ҏ(gu��)�?br />
让我们开始吧。假设你已经�~�写了你�?/font> WinMain 的基本代码：(x��)已经成功填充�?WNDCLASS �l�构�Q�注册了�H�口�c�，�q�且�~�写了消息��@环。现在你需要一个�ؓ(f��)你主函数�~�写
的消息处理函数�?br />
打开消息分流器Wizard。我们需要�ؓ(f��)我们的窗口选择消息�Q�因为MCW需要用它来生成我们的消息处理函数。如你所知，W(xu��)indows�E�序非常常见的处理消息是 WM_CLOSE �?br />WM_DESTROY �?WM_CREATE �Q�所以让我们选择消息分流器处理这些消息来创徏�H�口函数。然后，我们创徏�H�口函数的主体消息处理函数�?br />
在列表框中选择 WM_CLOSE , WM_DESTROY �?WM_CREATE 。因为此�H�口是我们程序的�ȝ��口，我们选用main做�ؓ(f��)�H�口的ID。这个窗口ID表识了我们的�H�口/对话框，�q�且
使分��宏和出理函��C��为后�~�。当�?d��ng)��你要使特定窗口的所有消息处理保持一致。观察下面的�~�辑框。它们显�C?span style="COLOR: rgb(204,0,0)"> HANDLE_MSG 分流宏和兌��的消息处理函数的原型�?/span>

但是�Q�等一�?.....我们说我们需要一个准备好的窗口处理函数。所以单几Z�?span style="FONT-WEIGHT: bold">Make Window Procedure”选定框，�q�且��认Window 单选按钮已�l�被选择了。现�?br />我们准备好了。要注意的是�Q�对话框的工作也像这��P��但是要改变处理函��Cؓ(f��)对话框类型�?br />
首先�Q�我们需要我们源代码的窗口处理函数。点几Z�?span style="FONT-WEIGHT: bold">Copy Macro”按钮（或者��?span style="FONT-STYLE: italic">Ctrl-M�Q�，最��化Wizard�Q�或者把它放��C��边）�Q�回��C��的IDE�q�且从剪贴板�_�脓(chu��ng)
�Q?span style="FONT-STYLE: italic">Ctrl-V�Q�代码到你的�H�口函数的位�|��?/font>Voil֙�Q�阿根�h(hu��n)拉丁语，认识的通知下）�Q�你可以得到像下面的代码�Q?
//
// main  Window Procedure
//
LRESULT CALLBACK main_WndProc (HWND hwnd, UINT msg, WPARAM wParam,   LPARAM lParam)
{
  switch(msg)
  {
    HANDLE_MSG (hwnd, WM_CLOSE, main_OnClose);
    HANDLE_MSG (hwnd, WM_CREATE, main_OnCreate);
    HANDLE_MSG (hwnd, WM_DESTROY, main_OnDestroy);
      //// TODO: Add window message crackers here
  default: return DefWindowProc (hwnd, msg, wParam, lParam);
  }
}

�q�个�H�口处理函数以三个消息分��宏展开工作�Q��ƈ且，通过TODO注释提示你记得必��d��q�里��d��消息分流器宏。当你只是要��d��一�?/font> HANDLE_MSG 宏到�H�口函数中时�Q?br />记得取消�?span style="FONT-WEIGHT: bold">Mke Window Procedure”选定框的选择�?/font>

但是�q�些代码现在�q�什么都做不了，因�ؓ(f��)我们�q�需要添加三个我们需要的消息处理函数。回到消息分��器Wizard工具的界面，�q�且单击�?span style="FONT-WEIGHT: bold">Copy Function”按钮。切
换到你的代码�Q�用鼠标定位��C��需要函��C��体插入的位置�Q�然后用Ctrl+V或者菜单Edit/Paste�_�脓(chu��ng)。Wizard自动生成函数�Q��?main 标识�H�口ID�Q��ƈ修正参数�c�d��
使之�W�合 WINDOWSX.H 头文件的�?

//
//Process WM_CLOSE message for window/dialog: main
//
void main_OnClose(HWND hwnd)
{
  // TODO: Add your message processing code here
}
//
//  Process WM_CREATE message for window/dialog: main
//
BOOL main_OnCreate(HWND hwnd, LPCREATESTRUCT lpCreateStruct)
{
  // TODO: Add your message processing code here
}
//
//  Process WM_DESTROY message for window/dialog: main
//
void main_OnDestroy(HWND hwnd)
{
  // TODO: Add your message processing code here
}

Wizard�q�可以自动生成开头注释，和TODO行以提醒你添加代码。现在你可以��d��消息处理了，可以是简单的处理处理逻辑�Q�或者复杂窗口函数。你也可以通过选定框移�?br />注释�?br />
更多的消息分��器Wizard�Ҏ(gu��)�?br />
消息�q��o(h��)

你可以过滤你暂时不打��处理的消息。单几Z�?span style="FONT-WEIGHT: bold">Filters..”按钮（或者Ctrl+L�Q�，你会(x��)打开下面对话框。列表的消息按类型分�c�（分类标准来自Microsoft Spy++的效果）�Q?br />你可以取消选定你不处理的消息�?br />

要注意的是在 v2.0 当前的问题是�Q�当你打开消息�q��o(h��)对话框时所有类型的消息都是选定的，当你点击OK�Q�之前选定的消息会(x��)丢失�Q�这�q�不意味着你粘贴到目标代码�?br />内容�?x��)消失）�?br />

��z�窗口模�?/span>

你可能需要减��消息分��Wizard�H�体的大��。这可以通过取消菜单 View �?�?span style="FONT-WEIGHT: bold">Show Target Code”选项的选定�Q�或者��用Ctrl+F11�Q�。主�H�口�?x��)取消目标代码区域�?x��)

�H�体透明�Q�取消注释和�|�顶

�Q�译注：(x��)Sorry�Q�暂不做��译了，你可以通过��试菜单 View 的其它几个选项自己体会(x��)^_^�Q?br />

未来�Ҏ(gu��)�?br />
下面的特性会(x��)在下一�ơ发布时实现�Q?/span>
帮助文�g�?
所有消息分��的参数和消息的完整帮助�?
支持WTL�Q?)
�H�口ID和配�|�保存（�q�个�?x��)在下一�?.x版本实现�Q��?
��目配置和“消息映��”（a la MFC�Q�（译注�Q�好像是西班牙语�Q�不认识:P�Q�（�q�个也会(x��)在之后的2.5版本实现�Q��?br />

快乐的编�E�！

我希望这个小工具可以让每�?Windows SDK �E�序员感兴趣�Q��ƈ且干净的编�?Win32 API �E�序。我乐于接受改进�q�个工具的主意。如果你发现�q�个�E�序很好用，��L(f��ng)��我发邮�g�Q�因为我非常高兴听到��M��好的意见�?br />
谢谢所有支持！�Q�You know who you are�Q�（译注�Q�不太明白这个要表达什么意思，“你知道你是谁！”乎�Q�）

��M��时候，打开我的主页�Q�你可以在那里找到这个程序的最新更新�?br />
历史�Q?br /> �?..

关于作者：(x��)Hern֙n Di Pietro

业余�E�序员�?br />
开始于1986�q�_(d��)��在Commodore 64上编写BASIC�E�序�?br />�?990�q�第一�?8086 PC 上开始编�?QB 4.x�?br />1995-1996�q��{�U�d��Visual Basic�?br />2002�q�_(d��)��23岁时开始编写C(j��)++�E�序�Q��ƈ�?Windows API 上瘾�?br />
主页�Q?http://usuarios.lycos.es/hernando

��山日志 2006-11-02 00:00 发表评论

��山日志 — Wed, 20 Sep 2006 15:18:00 GMT
    �q�是我第一此参加ACM竞赛�Q�我想也是最后一�ơ了。呵呵，要毕业啦^_^
    8�?8日接到�n�ƣ苹的电(sh��)话，说是有一个编�E�比赛要�l�队参加�Q�邀(g��)��h��加入她的队伍里�?a target="" class="" title="" href="/nj-blog/gallery/image/1211.html">
    因�ؓ(f��)不考研�Q�开学比较闲�Q�其实我一向是个闲人啦^_^�Q�，所以不假思烦(ch��)��q��应了�?br />三天后去�p�M��L��老师那里报名�Q�这才第一�ơ见到听��d��久的另一个队友：(x��)�U��v�?a target="" class="" title="" href="/nj-blog/gallery/image/1212.html">
    报完名才知道原来比赛是ACM啊！
    9�?0号预赛，勉强通过�?6号在哈工�E�的体育馆里册��Q�做��Z��5道题。大概组委会(x��)念在是黑龙江省的�W�一�ơ区域性竞赛，AC�?道题的全�l�了三等奖，一共有32个。呵呵，特�h(hu��n)甩卖了。最多的也只AC�?道题�Q�这些是一�{�奖�Q?支队伍�?道题的是二等奖，6支队伍�?br />
    从接到欣苹的通知那天到决赛，我只准备�?9天，感觉很仓促。如果上天能�l�我再来一�ơ的��Z��(x��)的话......
    不说废话了，�q�是十分高兴可以有这样一�ơ机�?x��)和�q�么多高水��^的�h同场竞技�Q�让我认识到自己在程序之路上原来�q�只是个井底之蛙。要学习(f��n)的东西还是很多，努力�Q�加油！
    而且意外收获了一个三�{�奖�Q�哈哈^_^

��山日志 2006-09-20 23:18 发表评论

Boost/utility里有些什�?(2)

��山日志 — Tue, 15 Aug 2006 16:24:00 GMT

2. 函数模板 checked_delete() �?/span> checked_array_delete()

定义了两个函数模�?/span> checked_delete �?/span> checked_array_delete �Q?/span> �q�有两个�c�L��?/span> checked_deleter �?/span> checked_array_deleter�?/span>

当我们利用指针删除一个对象的时候，对象�c�d��是否完整军_��了对象是否能够被正确删除。但是，如果你用 delete ��d��除一个类型�ƈ不完整的对象的指针，�~�译器�ƈ不会(x��)�l�你提供��M��错误信息�Q�好吧，有些�~�译器会(x��)�l�出警告信息�Q�但是程序员通常�?x��)忽略警告信息）�Q�但是这样做的结果却是对象的析构函数�Ҏ(gu��)��没有被调用�?/span>

所以，我们应当使用更严厉的手段��止�q�种事情的发生。比如说使用 checked_delete 代替 delete 来删除指针。当指针所指向的是一个不完全�c�d��Ӟ�� checked_delete �?x��)�ɾ~�译器发出错误信息�?/span>

class test�Q?/span> // 有声明，但是忘记了定义，或是忘记
           // 包含定义文�g�Q�test是一个不完全�c�d��
main()
{
test * pt = NULL;
delete pt;   // 有时�?x��)有警告信息�Q?br />             // 但有时什么都没有�?/span>
checked_delete(pt); // 发出错误信息�?/span>
}

checked_array_delete 是用来对应于 delete [ ] operator �Q?/span> checked_deleter �?/span> checked_array_deleter 是可以配接的仿函数版本�?/span>

3. 函数模板 next() �?/span> prior()
包括

template < class T > T next(T x);
template < class T, class Distance > T next(T x, Distance n);
template < class T > T prior(T x);
template < class T, class Distance > T prior(T x, Distance n);

函数模板对传入的指针�Q�智能指针或是�P代器做递增或递减�Q��ƈ传回它。用法如下：(x��)

const std::list < T > ::iterator p = get_some_iterator();
const std::list < T > ::iterator prev = boost::prior(p);
const std::list < T > ::iterator next = boost::next(prev, 2 );

事实上， T next(T x) �?/span> T prior(T x) ��分别调�?/span> operator++ �?/span> operator-- �Q��?/span> T next(T x, Distance n) �?/span> T prior(T x, Distance n) 则调�?/span> std::distance(T x, size_t n) �?

4.noncopyable �c?/span>

如果你需要设计一个不可以被复制的�c�，那么你就要明��地��它的拷贝构造函数和 operator = () 攑ֈ� private 声明下面�?/span> Boos\utility 准备了一个基�c?/span> noncopyable �Q�你只需要让你的�cȝ��承自 noncopyable ��可以获得这个性质。对你的�c�L��说这也是一个显式的声明�Q�“我是不可以被复制的�Q��?/span>
用法�Q?/span>

#include < boost / utility.hpp >

class ResourceLadenFileSystem : boost::noncopyable {

5 �Q�函数模�?/span> addressof()

函数模板�q�回一个对象的真实地址�Q�当然这是交�l�指针了�Q�：(x��)

template < typename T > inline T *                 addressof(T & v);
template < typename T > inline const T *          addressof( const T & v);
template < typename T > inline volatile T *       addressof( volatile T & v);
template < typename T > inline const volatile T * addressof( const volatile T & v);

我知道你惌��Q��ؓ(f��)什么不是简单的调用operator&()。因�?/span>c++允许重蝲operator&()�Q�所以有时��用它获得的�ƈ不是对象的真实地址�Q�而是�~�写重蝲operator&()代码的作者希望给你的那个。如果你却是希望获得的是�q�个对象的地址�Q��?/span>addressof():
#include <boost/utility.hpp>
struct useless_type {};

class nonaddressable {
  useless_type operator&() const;
};

void f() {
  nonaddressable x;
  nonaddressable* xp = boost::addressof(x);
  // nonaddressable* xpe = &x; //error! operator&()已经被重载，
                              //它返回的是useless_type的指�?/span>
}

上述的所有东襉K��可以��单的通过在你的源文�g开头处写上�Q?br />
#include <boost\utility.hpp>
using namespace boost;
��可以��用了。当然我是指你机器上已经有boost�q�个奇妙的库�Q��ƈ且正��配�|�^_^

��山日志 2006-08-16 00:24 发表评论

Boost/utility里有什么东西？(1)

��山日志 — Fri, 11 Aug 2006 15:59:00 GMT

�?/span> STL �?/span> utility 一��P�� boost/utility 里包含了一些实用的��工兗��?/span>

首先�?/span> Base-from-Member �Q?/span>

有时你可能需要依赖成员变量来初始化基�c�，像这��P��(x��)

class fdoutbuf
    : public std::streambuf
{
public :
     explicit fdoutbuf( int fd );
     //
};

class fdostream
    : public std::ostream
{
protected :
    fdoutbuf buf;
public :
     explicit fdostream( int fd )
        : buf( fd ), std::ostream( & buf )
        {}
     //
};

但是�Q�这�?/span> fdostream 的构造函数的初始化是错误的，因�ؓ(f��) c++ 语法要求基类的初始化要先于成员变量的初始化�?/span> Base-from-Member 提供的解决之道如下：(x��)

class fdoutbuf
    : public std::streambuf
{
public :
     explicit fdoutbuf( int fd );
     //
};

class fdostream
    : private boost::base_from_member < fdoutbuf >
    , public std::ostream
{
     // Helper typedef's
    typedef boost::base_from_member < fdoutbuf >   pbase_type;
    typedef std::ostream                        base_type;
public :
     explicit fdostream( int fd )
        : pbase_type( fd ), base_type( & member )
        {}
     //
};

模板�c?/span> template < typename MemberType, int UniqueID = 0 >
        class boost::base_from_member; 是一个外覆类�Q�姑且这么叫�?/span> ^_^ �Q��?br />如上�Q�私有��?/span> base_from_member �Q�原先的成员变量��做�?/span> base_from_member 的成员变�?/span> member 先于基类 base_type 初始化，�q�样所需的依赖关�p�d��以满��뀂事实上比这更好的是�Q?/span> base_from_member 的构造函数是模板函数�Q�它可以�?/span> 0 �?/span> 10 个参敎ͼ�参数�c�d��可以各不相同�?/span>

��山日志 2006-08-11 23:59 发表评论

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�l�制牛顿法复杂边界分形图 && ���L(f��ng)��扭�Ӟ��

�U�C�~�写的矩阵工具包

明白Boost�?span style="FONT-STYLE: italic">shared_ptr�?span style="FONT-STYLE: italic">deleter是如何工作的�Q?004

Message Crack Wizard for Win32 SDK Developer

Boost/utility里有些什�?(2)

Boost/utility里有什么东西？(1)

�l�制牛顿法复杂边界分形图 && ��L(f��ng)��扭�Ӟ��