读书笔记之：Boost程序库完全开发指南(ch5-16)

第5章

lexical_cast介绍

测试代码：

View Code

#include <iostream>
#include <string>
#include <boost/lexical_cast.hpp>
using namespace std;
using namespace boost;
void test1(){
    int x=lexical_cast<int>("100");
    long y=lexical_cast<long>("2000");
    float pai=lexical_cast<float>("3.14159e5");
    double e=lexical_cast<double>("2.71828");
    cout<<x<<" "<<y<<" "<<pai<<" "<<e<<endl;

    string str=lexical_cast<string>(456);
    cout<<str<<endl;
    cout<<lexical_cast<string>(0.6810)<<endl;
    cout<<lexical_cast<string>(0x10)<<endl;
}
int main(){
    test1();
}

boost中的format格式化输出库

format中为什么使用操作符重载

为什使用%

format格式化语法

测试代码：

View Code

format的性能

boost中的字符串算法string_algo

string_algo概述，其中包括五大类算法：大小写转换，判断式与分类，修剪，查找与替换，分割与合并

大小写转换

判断式

判断式（函数对象）

字符串查找

替换与删除

字符串分割

字符串合并

测试代码：

View Code

#include <iostream>
#include <string>
#include <vector>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
void test1(){
    string str("readme.txt");
    if(ends_with(str,"txt")){
        cout<<to_upper_copy(str)+" UPPER"<<endl;
    }
    replace_first(str,"readme","followme");
    cout<<str<<endl;

    vector<char> v(str.begin(),str.end());
    vector<char> v2=to_upper_copy(erase_first_copy(v,"txt"));
    for(int i=0;i<v2.size();i++)
        cout<<v2[i];
    cout<<endl;

}
void test2(){
    string str("I Don't Know.\n");
    cout<<to_upper_copy(str);
    cout<<str;
    to_lower(str);
    cout<<str;
}
void test3(){
    string str("Power Bomb");
    cout<<iends_with(str,"bomb")<<endl;
    cout<<ends_with(str,"bomb")<<endl;
    cout<<starts_with(str,"Pow")<<endl;
    cout<<contains(str,"er")<<endl;
}
int main(){
    test2();
}

第6章

第7章

array类摘要

测试代码：

View Code

#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <boost/array.hpp>
using namespace std;
using namespace boost;
int main(){
    const int N=10;
    array<int,N> ar;
    for(int i=0;i<N;i++)
        ar[i]=rand()%100;
    copy(ar.begin(),ar.end(),ostream_iterator<int>(cout," "));
    cout<<endl;

}

dynamic_bitset

测试代码：

View Code

#include <iostream>
#include <iterator>
#include <algorithm>
#include <boost/dynamic_bitset.hpp>
using namespace std;
using namespace boost;
int main(){
    int n;
    cin>>n;
    dynamic_bitset<> db(n);
    db.set();
    for(dynamic_bitset<>::size_type i=db.find_next(1);
            i!=dynamic_bitset<>::npos;
            i=db.find_next(i)){
        for(dynamic_bitset<>::size_type j=db.find_next(i);
                j!=dynamic_bitset<>::npos;
                j=db.find_next(j)){
            if(j%i==0)
                db[j]=0;
        }
    }
    for(dynamic_bitset<>::size_type i=db.find_next(2);
            i!=dynamic_bitset<>::npos;
            i=db.find_next(i))
        cout<<i<<", ";
    cout<<endl;
}

unordered:boost中的散列容器

boost中unordered散列集合简介：

散列集合unordered_set用法

测试代码：

View Code

#include <iostream>
#include <cstdlib>
#include <ext/hash_set>
#include <boost/assign.hpp>
#include <boost/unordered_set.hpp>
using namespace std;
using namespace boost;
using namespace __gnu_cxx;
template <class T>
void hash_func(){
    using namespace boost::assign;
    T s=(list_of(1),2,3,4,5);
    typename T::iterator p;
    for(p=s.begin();p!=s.end();++p)
        cout<<*p<<' ';
    cout<<endl;
    cout<<s.size()<<endl;

    s.clear();
    cout<<s.empty()<<endl;
    s.insert(8);
    s.insert(45);
    cout<<s.size()<<endl;
    cout<<*s.find(8)<<endl;

    s.erase(45);
    for(p=s.begin();p!=s.end();++p)
        cout<<*p<<' ';
    cout<<endl;
}
int main(){
    hash_func<hash_set<int> >();
    hash_func<unordered_set<int> >();
}

散列映射简介：unordered_map

undered_map散列映射用法

测试代码：

View Code

#include <iostream>
#include <cstdlib>
#include <ext/hash_map>
#include <boost/assign.hpp>
#include <boost/unordered_map.hpp>
using namespace std;
using namespace boost;
using namespace __gnu_cxx;
int main(){
    using namespace boost::assign;
    unordered_map<int,string> um=map_list_of(1,"one")(2,"two")(3,"three");
    um.insert(make_pair(10,"ten"));
    cout<<um[10]<<endl;
    um[11]="eleven";
    um[15]="fifteen";
    unordered_map<int,string>::iterator p;
    for(p=um.begin();p!=um.end();++p)
        cout<<p->first<<"-"<<p->second<<",";
    cout<<endl;

    um.erase(11);
    cout<<um.size()<<endl;

    hash_map<int,string> hm=map_list_of(4,"four")(5,"five")(6,"six");

    hash_map<int,string>::iterator q;
    for(q=hm.begin();q!=hm.end();++q)
        cout<<q->first<<"-"<<q->second<<",";
    cout<<endl;

}

性能比较：

测试代码：

View Code

#include <iostream>
#include <typeinfo>
#include <set>
#include <ext/hash_set>
#include <boost/unordered_set.hpp>
#include <boost/random.hpp>
#include <boost/date_time/gregorian/gregorian.hpp>
//#include <boost/date_time.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#define BOOST_DATE_TIME_SOURCE
#define BOOSt_DATE_TIME_POSIX_TIME_STD_CONFIG
using namespace std;
using namespace boost;
//using namespace boost::gregorian;
using namespace boost::posix_time;
using namespace __gnu_cxx;

template <class Clock=microsec_clock>
class basic_ptimer{
    public:
        basic_ptimer(){
            restart();
        }
        void restart(){
            _start_time=Clock::local_time();
        }
        void elapsed()const{
            cout<<Clock::local_time()-_start_time;
        }
        ~basic_ptimer(){
            elapsed();
        }
    private:
        ptime _start_time;
};
typedef basic_ptimer<microsec_clock> ptimer;

template <class T>
void fill_set(T &c){
    variate_generator<mt19937,uniform_int<> >
        gen(mt19937(),uniform_int<>(0,100));
    for(int i=0;i<10000;++i)
        c.insert(gen());
}
template <class T>
void test_perform(){
    T c;
    cout<<typeid(c).name()<<' ';
    {
        ptimer t;
        fill_set(c);
    }
    cout<<" ";
    {
        ptimer t;
        c.count(10);
    }
    cout<<" ";
    {
        ptimer t;
        c.find(20);
    }
    cout<<endl;
}
int main(){
    test_perform<multiset<int> >();
    test_perform<hash_multiset<int> >();
    test_perform<unordered_multiset<int> >();
}

boost中的树形结构：property_tree

读取配置信息

写入配置信息：

conf.xml文件内容及测试代码：

View Code

<conf>
    <gui>1</gui>
    <theme>matrix</theme>
    <urls>
        <url>http://www.url1.com</url>
        <url>http://www.url2.com</url>
        <url>http://www.url3.com</url>
    </urls>
    <clock_style>24</clock_style>
</conf>

View Code

#include <iostream>
#include <string>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
using std::cout;
using std::endl;
using std::string;
void parser(){
    using namespace boost::property_tree;
    ptree pt;
    read_xml("conf.xml",pt);
    cout<<pt.get<string>("conf.theme")<<endl;
    cout<<pt.get<int>("conf.clock_style")<<endl;
    cout<<pt.get<long>("conf.gui")<<endl;
    cout<<pt.get("conf.no_prop",100)<<endl;
    ptree child;
    ptree::iterator pos;
    child=pt.get_child("conf.urls");
    for(pos=child.begin(); pos!=child.end();++pos)
        cout<<pos->second.data()<<" ";
    cout<<endl;
    cout<<"==========writing==========="<<endl;
    pt.put("conf.theme","Matrix Reloaded");
    pt.put("conf.clock_style",12);
    pt.put("conf.gui",0);
    pt.put("conf.urls.url","http://www.url4.org");
    pt.put("conf.urls.url","http://www.url5.org");

    write_xml(cout,pt);
}
int main(){
    parser();
}

第8章算法

foreach使用

测试代码：

View Code

#include <iostream>
#include <vector>
#include <string>
#include <boost/foreach.hpp>
#include <boost/assign.hpp>
using namespace std;
void  foreach_(){
    using namespace boost::assign;
    vector<int> v=(list_of(1),2,3,4,5);
    BOOST_FOREACH(int x,v){
        cout<<x<<" ";
    }
    cout<<endl;

    string str("boost foreach");
    BOOST_FOREACH(char& c,str){
        cout<<c<<"-";
    }
    cout<<endl;
}
int main(){
    foreach_();
}

第9章

伪随机数random

测试代码：

View Code

#include <iostream>
#include <ctime>
#include <boost/random.hpp>
using namespace std;
using namespace boost;
void test1(){
    mt19937 rng(time(0));
    for(int i=0;i<100;i++){
        cout<<rng()<<" ";
    }
    cout<<endl;
}
int main(){
    test1();
}

第12章多线程