cplusplus - 随笔分类 - strorehouse

摘要：昨天看到有人在说这个，确实比较有意思。既不违反语法，又比较出乎意料。就像C里面那种switch里嵌套一层do while语句一样。void cpy(char* to, char* from, size_t count){ register n = (count + 7) / 8; switch (count % 8) { case 0: do { *to = *from++; case 7: *to = *from++; case 6: ... 阅读全文

posted @ 2013-05-02 09:21 strorehouse

c++ 判断32位/64位机器

摘要：某些人会考虑用long类型的长度来作为判断的标准，这样不是一个好的答案。我认为比较好的答案是利用虚拟地址的位数：1 int main()2 {3 4 #ifdef __x86_64__5 assert(sizeof(char *) == 8);6 #endif7 return 0;8 }然后见到别人提了一个这样的问题：如果是64位的机器装了32位的系统，你怎么判断呢？A:1. 直接读取/proc/cpuinfo2.更底层点的做法：使用汇编指令cpuid 阅读全文

posted @ 2013-04-24 09:46 strorehouse

zoj1078

摘要：阅读全文

posted @ 2013-04-10 10:42 strorehouse

5种值类型

摘要：REFER：SOWhat are these new categories of expressions?The FCD (n3092) has an excellent description:— An lvalue (so called, historically, because lvalues could appear on the left-hand side of an assignment expression) designates a function or an object. [ Example: If E is an expression of pointer type 阅读全文

posted @ 2013-04-08 19:52 strorehouse

Convertion between Number and String

摘要：REFER:SOAs of theC++11standard, string-to-number conversion and vice-versa are built in into the standard library. All the following functions are present in<string>(as per paragraph 21.5).string to numericfloat stof(const string& str, size_t *idx = 0);double stod(const string& str, si 阅读全文

posted @ 2013-04-08 19:48 strorehouse

New/delete VS malloc/free

摘要：REFER:SO中文社区见到的答案,不提也罢new/deleteAllocate/release memoryMemory allocated from 'Free Store'Returns a fully typed pointer.new (standard version) never returns a NULL (will throw on failure)Are called with Type-ID (compiler calculates the size)Has a version explicitly to handle arrays.Reallocati 阅读全文

posted @ 2013-04-08 19:33 strorehouse

C++ mechanisms for polymorphism

摘要：C++ mechanisms for polymorphismExplicit programmer-specified polymorphismYou can writef()such that it can operate on multiple types in any of the following ways:Preprocessing:#define f(X)((X)+=2)// (note: in real code, use a longer uppercase name for a macro!)Overloading:void f(int& x){ x +=2;}v 阅读全文

posted @ 2013-04-04 20:10 strorehouse

c++ default functions

摘要：网上某些流传的答案是错误的，以讹传讹，呵呵In c++ 03:default ctorcopy ctorassignment operatordefault destructorIn c++ 0x:default ctorcopy ctorassignment operatordefault destructormove constructormove-assignment operator 阅读全文

posted @ 2013-04-02 20:15 strorehouse

Singleton pattern in C++

摘要：View Code /*refer:http://stackoverflow.com/questions/270947/can-any-one-provide-me-a-sample-of-singleton-in-c/271104#271104 */#include <vector>#include <string>#include <iostream>using namespace std;class Sin{ public: static Sin& getInstance() { static Sin instance; ... 阅读全文

posted @ 2013-04-01 21:21 strorehouse

leetcode -- 一个算法面试题相关的网站

摘要：去年就在某牛人的博客上见到了，现在准备去玩玩。做题的方式跟Topcoder类似，刚刚去水了一题"Valid Palindrome" 1 class Solution { 2 public: 3 bool isPalindrome(string s) { 4 // Start typing your C/C++ solution below 5 // DO NOT write int main() function 6 string alnumstr; 7 transform(s.begin(), s.end(), s.... 阅读全文

posted @ 2013-03-08 18:26 strorehouse

Memory management demo from TCPL

摘要：1 /* 2 simple memory manage demo from TCPL 3 should be compiled in unix 4 debug to see how it works 5 */ 6 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <unistd.h> 10 11 typedef long Align; 12 13 union header 14 { 15 struct 16 { 17 union header* p... 阅读全文

posted @ 2012-10-29 14:27 strorehouse

随笔分类 - cplusplus