一个万用的hash_function

将hash函数封装成类对象
hash_val进行拆解传入参数，进行循环

每次拆解一个参数，都需要更新种子

TR1的工具，）0x9e3779b9是黄金比例数字0.618
测试
当没有指定hash函数时，用默认的hash函数，但是针对特殊的类型，有自己特化的hash函数
Tuple用例

测试
实现，递归的继承实现自动添加任意多个函数，需要有终止条件无参数偏特化版本

元组大小决定由类的继承关系决定
type traits

测试，traits回答type的类型
区别拷贝和‘搬运’构造函数
cout

cout继承关系，把已有的类型放入cout才可以输出
movable元素对于deque速度现的影响

深浅拷贝

使用move后，保证原来的地址不在使用
测试函数

using namespace std;
const long ASIZE  =   500000L;//----------------------------------------------------
#include <iostream>
#include <cstdio>  //snprintf()
#include <cstdlib> //RAND_MAX
#include <cstring> //strlen(), memcpy()
#include <string> 
using std::cin;
using std::cout;
using std::string;//以下 MyString 是為了測試 containers with moveable elements 效果.  
class MyString { 
public: static size_t DCtor;    //累計 default-ctor 的呼叫次數 static size_t Ctor;     //累計 ctor      的呼叫次數 static size_t CCtor;    //累計 copy-ctor 的呼叫次數 static size_t CAsgn;    //累計 copy-asgn 的呼叫次數 static size_t MCtor;    //累計 move-ctor 的呼叫次數 static size_t MAsgn;    //累計 move-asgn 的呼叫次數            static size_t Dtor; //累計 dtor 的呼叫次數 
private:     char* _data; size_t _len; void _init_data(const char *s) { _data = new char[_len+1]; memcpy(_data, s, _len); _data[_len] = '\0'; } 
public: //default ctorMyString() : _data(NULL), _len(0) { ++DCtor;  }//ctorMyString(const char* p) : _len(strlen(p)) { ++Ctor; _init_data(p); } // copy ctorMyString(const MyString& str) : _len(str._len) { ++CCtor;      _init_data(str._data);  //COPY} //move ctor, with "noexcept"MyString(MyString&& str) noexcept : _data(str._data), _len(str._len)  {  ++MCtor;    str._len = 0;       str._data = NULL;   //避免 delete (in dtor) }//copy assignmentMyString& operator=(const MyString& str) { ++CAsgn;     if (this != &str) { if (_data) delete _data;  _len = str._len; _init_data(str._data);  //COPY! } else {// Self Assignment, Nothing to do.   }return *this; } //move assignmentMyString& operator=(MyString&& str) noexcept {   ++MAsgn;    if (this != &str) { if (_data) delete _data; _len = str._len; _data = str._data;  //MOVE!str._len = 0; str._data = NULL;   //避免 deleted in dtor } return *this; }//dtorvirtual ~MyString() {   ++Dtor;                 if (_data) {delete _data;   }}       bool operator<(const MyString& rhs) const    //為了讓 set較大小  {return std::string(this->_data) < std::string(rhs._data);    //借用事實：string 已能比較大小. }bool operator==(const MyString& rhs) const   //為了讓 set 判斷相等. {return std::string(this->_data) == std::string(rhs._data);   //借用事實：string 已能判斷相等. }   char* get() const { return _data; }
}; 
size_t MyString::DCtor=0;   
size_t MyString::Ctor=0;     
size_t MyString::CCtor=0;
size_t MyString::CAsgn=0;
size_t MyString::MCtor=0;
size_t MyString::MAsgn=0;
size_t MyString::Dtor=0;namespace std   //必須放在 std 內 
{
template<> 
struct hash<MyString>   //這是為了 unordered containers 
{size_t operator()(const MyString& s) const noexcept{  return hash<string>()(string(s.get()));  }  //借用現有的 hash<string> (in ...\include\c++\bits\basic_string.h)
};
}
//-----------------
//以下 MyStrNoMove 是為了測試 containers with no-moveable elements 效果.  
class MyStrNoMove { 
public: static size_t DCtor;    //累計 default-ctor 的呼叫次數 static size_t Ctor;     //累計 ctor      的呼叫次數 static size_t CCtor;    //累計 copy-ctor 的呼叫次數 static size_t CAsgn;    //累計 copy-asgn 的呼叫次數 static size_t MCtor;    //累計 move-ctor 的呼叫次數 static size_t MAsgn;    //累計 move-asgn 的呼叫次數            static size_t Dtor;     //累計 dtor 的呼叫次數 
private:     char* _data; size_t _len; void _init_data(const char *s) { _data = new char[_len+1]; memcpy(_data, s, _len); _data[_len] = '\0'; } 
public: //default ctorMyStrNoMove() : _data(NULL), _len(0) {  ++DCtor; _init_data("jjhou"); }//ctorMyStrNoMove(const char* p) : _len(strlen(p)) { ++Ctor;  _init_data(p); } // copy ctorMyStrNoMove(const MyStrNoMove& str) : _len(str._len) { ++CCtor;     _init_data(str._data);  //COPY} //copy assignmentMyStrNoMove& operator=(const MyStrNoMove& str) { ++CAsgn;if (this != &str) { if (_data) delete _data;  _len = str._len; _init_data(str._data);  //COPY! } else {// Self Assignment, Nothing to do.   }return *this; } //dtorvirtual ~MyStrNoMove() {       ++Dtor;             if (_data) {delete _data;   }}       bool                                            operator<(const MyStrNoMove& rhs) const     //為了讓 set 比較大小 {return string(this->_data) < string(rhs._data);  //借用事實：string 已能比較大小. }   bool                                            operator==(const MyStrNoMove& rhs) const    //為了讓 set 判斷相等. {return string(this->_data) == string(rhs._data);  //借用事實：string 已能判斷相等. } char* get() const { return _data; } 
}; 
size_t MyStrNoMove::DCtor=0;    
size_t MyStrNoMove::Ctor=0;  
size_t MyStrNoMove::CCtor=0;
size_t MyStrNoMove::CAsgn=0;
size_t MyStrNoMove::MCtor=0;
size_t MyStrNoMove::MAsgn=0;
size_t MyStrNoMove::Dtor=0;namespace std   //必須放在 std 內 
{
template<> 
struct hash<MyStrNoMove>    //這是為了 unordered containers 
{size_t operator()(const MyStrNoMove& s) const noexcept{  return hash<string>()(string(s.get()));  }  //借用現有的 hash<string> (in ...\4.9.2\include\c++\bits\basic_string.h)
};
}//----------------------------------------------------
#include <iostream>
#include <cstdio>  //snprintf()
#include <cstdlib> //RAND_MAX
#include <string> 
#include <algorithm> 
#include <list> 
#include <forward_list> 
using std::cin;
using std::cout;
using std::string;
using std::max;
using std::min;namespace jj00
{bool strLonger(const string& s1, const string& s2) {return s1.size() < s2.size();
}       void test_misc()
{cout << "\ntest_misc().......... \n";//以下這些是標準庫的眾多容器的 max_size() 計算方式.  cout << size_t(-1) << endl;                             //4294967295cout << size_t(-1)/sizeof(long) << endl;                //1073741823cout << size_t(-1)/sizeof(string) << endl;              //1073741823cout << size_t(-1)/sizeof(_List_node<string>) << endl;  //357913941cout << size_t(-1)/sizeof(_Fwd_list_node<string>) << endl; //536870911cout << "RAND_MAX= " << RAND_MAX << endl;   //32767cout << min( {2,5,8,9,45,0,81} ) << endl;  //0cout << max( {2,5,8,9,45,0,81} ) << endl;  //81vector<int> v {2,5,8,9,45,0,81};               cout << "max of     zoo and hello : " << max(string("zoo"), string("hello")) << endl;              //zoocout << "longest of zoo and hello : " << max(string("zoo"), string("hello"), strLonger) << endl;   //hello    cout << hash<MyString>()(MyString("Ace")) << endl;      //1765813650cout << hash<MyString>()(MyString("Stacy")) << endl;    //2790324277cout << "MyString(zoo) < MyString(hello) ==> " << (MyString("zoo") < MyString("hello")) << endl;    //0cout << "MyString(zoo) == MyString(hello) ==> " << (MyString("zoo") == MyString("hello")) << endl;  //0   cout << "MyStrNoMove(zoo) < MyStrNoMove(hello) ==> " << (MyStrNoMove("zoo") < MyStrNoMove("hello")) << endl;     //0cout << "MyStrNoMove(zoo) == MyStrNoMove(hello) ==> " << (MyStrNoMove("zoo") == MyStrNoMove("hello")) << endl;   //0//以上建構了 6 個 MyString objects 和 4 個 MyStrNoMove objects，都是暫時生命.    
}
}    
//--------------------------------------------------
#include <typeinfo>  //typeid()
template<typename T>
void output_static_data(const T& myStr)
{cout << typeid(myStr).name() << " -- " << endl; cout << " CCtor=" << T::CCtor   << " MCtor=" << T::MCtor << " CAsgn=" << T::CAsgn        << " MAsgn=" << T::MAsgn << " Dtor="  << T::Dtor << " Ctor="  << T::Ctor << " DCtor=" << T::DCtor        << endl;   
}#include <ctime>  //clock_t, clock()
template<typename M, typename NM>   
void test_moveable(M c1, NM c2, long& value)
{   
char buf[10];//測試 move cout << "\n\ntest, with moveable elements" << endl;         typedef typename iterator_traits<typename M::iterator>::value_type  V1type;     
clock_t timeStart = clock();                                for(long i=0; i< value; ++i){snprintf(buf, 10, "%d", rand());            auto ite = c1.end();c1.insert(ite, V1type(buf));    }cout << "construction, milli-seconds : " << (clock()-timeStart) << endl;    cout << "size()= " << c1.size() << endl;        output_static_data(*(c1.begin()));timeStart = clock();    
M c11(c1);                      cout << "copy, milli-seconds : " << (clock()-timeStart) << endl;    timeStart = clock();    
M c12(std::move(c1));                       cout << "move copy, milli-seconds : " << (clock()-timeStart) << endl;timeStart = clock();    c11.swap(c12);                      cout << "swap, milli-seconds : " << (clock()-timeStart) << endl;        //測試 non-moveable   cout << "\n\ntest, with non-moveable elements" << endl;     typedef typename iterator_traits<typename NM::iterator>::value_type  V2type;                timeStart = clock();                                for(long i=0; i< value; ++i){snprintf(buf, 10, "%d", rand());            auto ite = c2.end();c2.insert(ite, V2type(buf));    }cout << "construction, milli-seconds : " << (clock()-timeStart) << endl;    cout << "size()= " << c2.size() << endl;            output_static_data(*(c2.begin()));timeStart = clock();    
NM c21(c2);                     cout << "copy, milli-seconds : " << (clock()-timeStart) << endl;    timeStart = clock();    
NM c22(std::move(c2));                      cout << "move copy, milli-seconds : " << (clock()-timeStart) << endl;timeStart = clock();    c21.swap(c22);                      cout << "swap, milli-seconds : " << (clock()-timeStart) << endl;            
}
（六）STL周边浅谈

一个万用的hash_function

Tuple用例

type traits

cout

movable元素对于deque速度现的影响

测试函数
