boost常用庫案例

http://www.cnblogs.com/wangkangluo1/archive/2011/07/19/2110746.html
1.boost::any

boost::any是一種通用的數據類型，可以將各種類型包裝后統一放入容器內，最重要的它是類型安全的。有點象COM里面的variant。

使用方法：
any::type() 返回包裝的類型

any_cast可用于any到其他類型的轉化

#include <boost/any.hpp>

void test_any() {typedef std::vector<boost::any> many;many a;a.push_back(2);a.push_back(string("test"));for(unsigned int i=0;i<a.size();++i){cout<<a[i].type().name()<<endl;try{int result = any_cast<int>(a[i]);cout<<result<<endl;}catch(boost::bad_any_cast & ex){cout<<"cast error:"<<ex.what()<<endl;}} }

2.boost::array
boost::array僅僅是對數組一層薄薄的封裝，提供跟各種算法配合的iterator,使用方法很簡單。注意：可以使用{}來初始化array,因為array所有的成員變量都是public的。
#include <boost/array.hpp> void test_array() {array<int,10> ai = {1,2,3};for(size_t i=0;i<ai.size();++i){cout<<ai[i]<<endl;} }

3.boost::lexical_cast
lexical_cast用于將字符串轉換成各種數字類型(int,float,short etc.)。
#include <boost/lexical_cast.hpp> void test_lexical_cast() {int i = boost::lexical_cast<int>("123");cout << i << endl; }

4.boost::format
boost::format是用于替代c里面的sprintf，優點是類型安全，不會因為類型和參數不匹配而導致程序崩潰了，而且還可以重復使用參數。
#include <boost/format.hpp> void test_format() {cout << boost::format("writing %1%, x=%2% : %3%-th try")% "toto"% 40.23% 50<<endl;format f("a=%1%,b=%2%,c=%3%,a=%1%");f % "string" % 2 % 10.0;cout << f.str() << endl; }

5.boost::tokenizer
boost::tokenizer是用于切割字符串的，類似于Java里面的StringTokenizer。
#include <boost/tokenizer.hpp>
void test_tokenizer()
{
string s("This is ?, a ,test!");
boost::tokenizer<> tok(s);
for(tokenizer<>::iterator beg=tok.begin(); beg!=tok.end();++beg)
{
cout << *beg << " ";
}
}


6.boost::thread
boost::thread是為了提供跨平臺的thread機制。利用boost::function來完成委托。
#include <boost/thread.hpp>
void mythread()
{
cout<<"hello,thread!"<<endl;
}
void test_thread()
{
boost::function< void () > f(mythread);
boost::thread t(f);
t.join();
cout<<"thread is over!"<<endl;
}


7.boost::serialization
boost::serialization提供object的序列化功能。而且提供好幾種序列化的格式，比如text,binary,xml。
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/archive/xml_oarchive.hpp>
void test_serialization()
{
boost::archive::text_oarchive to(cout , boost::archive::no_header);
int i = 10;
string s = "This is a test ";
to & i;
to & s;
ofstream f("test.xml");
boost::archive::xml_oarchive xo(f);
xo & BOOST_SERIALIZATION_NVP(i) & BOOST_SERIALIZATION_NVP(s);
boost::archive::text_iarchive ti(cin , boost::archive::no_header);
ti & i & s;
cout <<"i="<< i << endl;
cout <<"s="<< s << endl;
}


8.boost::function
boost::function就是所謂的泛函數，能夠對普通函數指針，成員函數指針，functor進行委托，達到遲調用的效果。
#include <boost/function.hpp>
int foo(int x,int y)
{
cout<< "(foo invoking)x = "<<x << " y = "<< y <<endl;
return x+y;
}
struct test
{
int foo(int x,int y)
{
cout<< "(test::foo invoking)x = "<<x << " y = "<< y <<endl;
return x+y;
}
};
void test_function()
{
boost::function<int (int,int)> f;
f = foo;
cout << "f(2,3)="<<f(2,3)<<endl;
test x;
/*f = std::bind1st(std::mem_fun(&test::foo), &x);*/
boost::function<int (test*,int,int)> f2;
f2 = &test::foo;

cout << "f2(5,3)="<<f2(&x,5,3)<<endl;
}


9.boost::shared_ptr
boost::shared_ptr就是智能指針的實現，不象std::auto_ptr，它是可以stl的容器一起使用的，非常的方便。
#include <boost/shared_ptr.hpp>
class Shared
{
public:
Shared()
{
cout << "ctor() called"<<endl;
}
Shared(const Shared & other)
{
cout << "copy ctor() called"<<endl;
}
~Shared()
{
cout << "dtor() called"<<endl;
}
Shared & operator = (const Shared & other)
{
cout << "operator = ?called"<<endl;
}
};
void test_shared_ptr()
{
typedef boost::shared_ptr<Shared> SharedSP;
typedef vector<SharedSP> VShared;
VShared v;
v.push_back(SharedSP(new Shared()));
v.push_back(SharedSP(new Shared()));
}
========

boost asio 簡單示例

http://blog.chinaunix.net/uid-1720597-id-85507.html
客戶端:
#include <iostream>
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>


using boost::asio::ip::tcp;
using boost::asio::ip::address;


class session: public boost::enable_shared_from_this<session> {
public:
session(boost::asio::io_service &io_service, tcp::endpoint &endpoint)
: io_service_(io_service), socket_(io_service), endpoint_(endpoint)
{?
}?


void start() {
socket_.async_connect(endpoint_,
boost::bind(&session::handle_connect,?
shared_from_this(),?
boost::asio::placeholders::error));
}?


private:
void handle_connect(const boost::system::error_code &error) {
if (error) {
if (error.value() != boost::system::errc::operation_canceled) {
std::cerr << boost::system::system_error(error).what() << std::endl;
}?


socket_.close();
return;
}?


static tcp::no_delay option(true);
socket_.set_option(option);


strcpy(buf, "Hello World!\n");
boost::asio::async_write(socket_,?
boost::asio::buffer(buf, strlen(buf)),
boost::bind(&session::handle_write,?
shared_from_this(),?
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}?


void handle_write(const boost::system::error_code& error, size_t bytes_transferred) {
memset(buf, sizeof(buf), 0);?
boost::asio::async_read_until(socket_,?
sbuf,
"\n",
boost::bind(&session::handle_read,
shared_from_this(),
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}


void handle_read(const boost::system::error_code& error, size_t bytes_transferred) {
std::cout << buf << std::endl;
}


private:
boost::asio::io_service &io_service_;
tcp::socket socket_;
tcp::endpoint &endpoint_;
char buf[1024];
boost::asio::streambuf sbuf;
};


typedef boost::shared_ptr<session> session_ptr;


int main(int argc, char* argv[])
{
boost::asio::io_service io_service;
tcp::endpoint endpoint(address::from_string("192.168.1.1"), 10028);


session_ptr new_session(new session(io_service, endpoint));
new_session->start();
io_service.run();
return 0;
}


服務器:
#include <string.h>
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>


using boost::asio::ip::tcp;
using boost::asio::ip::address;


class session: public boost::enable_shared_from_this<session> {
public:
session(boost::asio::io_service &io_service): socket_(io_service)
{?
}?


void start() {
static tcp::no_delay option(true);
socket_.set_option(option);


boost::asio::async_read_until(socket_,?
sbuf_,
"\n",
boost::bind(&session::handle_read,?
shared_from_this(),?
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}?


tcp::socket &socket() {
return socket_;
}?


private:
void handle_write(const boost::system::error_code& error, size_t bytes_transferred) {
boost::asio::async_read_until(socket_,?
sbuf_,
"\n",
boost::bind(&session::handle_read,?
shared_from_this(),?
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}?


void handle_read(const boost::system::error_code& error, size_t bytes_transferred) {
boost::asio::async_write(socket_,?
sbuf_,
boost::bind(&session::handle_write,?
shared_from_this(),?
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}


private:
tcp::socket socket_;
boost::asio::streambuf sbuf_;
};


typedef boost::shared_ptr<session> session_ptr;


class server {
public:
server(boost::asio::io_service &io_service, tcp::endpoint &endpoint)
: io_service_(io_service), acceptor_(io_service, endpoint)
{
session_ptr new_session(new session(io_service_));
acceptor_.async_accept(new_session->socket(),
boost::bind(&server::handle_accept,
this,
new_session,
boost::asio::placeholders::error));
}


void handle_accept(session_ptr new_session, const boost::system::error_code& error) {
if (error) {
return;
}


new_session->start();
new_session.reset(new session(io_service_));
acceptor_.async_accept(new_session->socket(),
boost::bind(&server::handle_accept,
this,
new_session,
boost::asio::placeholders::error));
}


void run() {
io_service_.run();
}


private:
boost::asio::io_service &io_service_;
tcp::acceptor acceptor_;
};


int main(int argc, char* argv[])
{
boost::asio::io_service io_service;
tcp::endpoint endpoint(address::from_string("192.168.1.1"), 10028);


server s(io_service, endpoint);
s.run();
return 0;
}


編譯:?
g++ -Wall -o client client.cpp -lboost_system
g++ -Wall -o server server.cpp -lboost_system


這里需要注意的是: async_write, async_read, async_read_until 都是需要達到特定條件才會調用回調函數,?
在調用回調函數之前, 不能再次調用, 否則接收到的數據很可能是亂的. 所以, 在實際代碼當中, 會有一個寫緩沖隊列, 當需要write的時, 先放到隊列中, 如果隊列個數為1, 則調用async_write, 否則等待函數回調, 當函數回調時將首個元素從隊列中移除, 然后接著發送下一個, 直到隊列為空.


對于client, 由于is_open在async_connect之后就是true狀態了, 因此在async_connect回調返回之前沒有方法知道是否已經連接成功, 實際代碼當中一般會增加一個變量以表示該套接字是否已經允許發送數據.
========

C++之BOOST字符串查找示例

http://www.jb51.net/article/56642.htm


這篇文章主要介紹了C++之BOOST字符串查找的方法,實例演示了boost針對字符串的查找、判定及替換等操作,


本文實例講述了C++中BOOST字符串查找的方法，分享給大家供大家參考。具體方法如下：
BOOST ?字符串查找示例
復制代碼 代碼如下:
#include <string> ?
#include <iostream> ?
#include <algorithm> ?
#include <functional> ?
#include <boost/algorithm/string/case_conv.hpp> ?
#include <boost/algorithm/string/find.hpp> ?

using namespace std; ?
using namespace boost; ?

int main() ?
{ ? ?
cout << "* Find Example *" << endl << endl; ?

string str1("abc___cde___efg"); ?
string str2("abc"); ?

// find "cde" substring ?
iterator_range<string::iterator> range=find_first( str1, string("cde") ); ?

// convert a substring to upper case ??
// note that iterator range can be directly passed to the algorithm ?
to_upper( range ); ?

cout << "str1 with upper-cased part matching cde: " << str1 << endl; ?

// get a head of the string ?
iterator_range<string::iterator> head=find_head( str1, 3 ); ?
cout << "head(3) of the str1: " << string( head.begin(), head.end() ) << endl; ?

// get the tail ?
head=find_tail( str2, 5 ); ?
cout << "tail(5) of the str2: " << string( head.begin(), head.end() ) << endl; ?

// char processing ?
char text[]="hello dolly!"; ?
iterator_range<char*> crange=find_last(text,"ll"); ?

// transform the range ( add 1 ) ?
transform( crange.begin(), crange.end(), crange.begin(), bind2nd( plus<char>(), 1 ) ); ?
// uppercase the range ?
to_upper( crange ); ?

cout << text << endl; ?

cout << endl; ?

return 0; ?
}
boost 判定函數的使用
復制代碼 代碼如下:
#include <string> ?
#include <iostream> ?
#include <functional> ?
#include <boost/algorithm/string/predicate.hpp> ?
#include <boost/algorithm/string/classification.hpp> ?
#include <boost/bind.hpp>?
using namespace std; ?
using namespace boost;?
int main() ?
{ ?
cout << "* Predicate Example *" << endl << endl; ?

string str1("123xxx321"); ?
string str2("abc"); ?

// Check if str1 starts with '123' ?
cout << "str1 starts with \"123\": " << ??
(starts_with( str1, string("123") )?"true":"false") << endl; ??

// Check if str1 ends with '123' ?
cout << "str1 ends with \"123\": " << ??
(ends_with( str1, string("123") )?"true":"false") << endl; ??

// Check if str1 containes 'xxx' ?
cout << "str1 contains \"xxx\": " << ??
(contains( str1, string("xxx") )?"true":"false") << endl; ??

// Check if str2 equals to 'abc' ?
cout << "str2 equals \"abc\": " << ??
(equals( str2, string("abc") )?"true":"false") << endl; ??

// Classification functors and all predicate ?
if ( all(";.,", is_punct() ) ) ?
{ ?
cout << "\";.,\" are all punctuation characters" << endl; ? ?
} ?

// Classification predicates can be combined ??
if ( all("abcxxx", is_any_of("xabc") && !is_space() ) ) ?
{ ?
cout << "true" << endl; ?
} ?

cout << endl; ?

return 0; ?
}
boost替換示例
復制代碼 代碼如下:
#include <string> ?
#include <iostream> ?
#include <iterator> ?
//#include <boost/algorithm/string/replace.hpp> ?
//#include <boost/algorithm/string/erase.hpp> ?
//#include <boost/algorithm/string/case_conv.hpp> ?
#include <boost/algorithm/string.hpp> ?

//Following two includes contain second-layer function. ?
//They are already included by first-layer header ?

//#include <boost/algorithm/string/replace2.hpp> ?
//#include <boost/algorithm/string/find2.hpp> ?

using namespace std; ?
using namespace boost; ?

// uppercase formatter ?
/* ?
Convert an input to upper case. ??
Note, that this formatter can be used only on std::string inputs. ?
*/ ?
inline string upcase_formatter( ??
const iterator_range<string::const_iterator>& Replace ) ?
{ ?
string Temp(Replace.begin(), Replace.end()); ?
to_upper(Temp); ?
return Temp; ?
} ?

int main() ?
{ ? ?
cout << "* Replace Example *" << endl << endl; ?

string str1("abc___cde___efg"); ?

// Erase 6-9th characters from the string ?
cout << "str1 without 6th to 9th character:" << ?
erase_range_copy( str1, make_iterator_range(str1.begin()+6, str1.begin()+9) ) << endl; ?

// Replace 6-9th character with '+++' ?
cout << "str1 with 6th to 9th character replaced with '+++': " << ??
replace_range_copy( ??
str1, make_iterator_range(str1.begin()+6, str1.begin()+9), "+++" ) << endl; ?

cout << "str1 with 'cde' replaced with 'XYZ': "; ?

// Replace first 'cde' with 'XYZ'. Modify the input ?
replace_first_copy( ostream_iterator<char>(cout), str1, "cde", "XYZ" ); ?
cout << endl; ?

// Replace all '___' ?
cout << "str1 with all '___' replaced with '---': " << ??
replace_all_copy( str1, "___", "---" ) << endl; ?

// Erase all '___' ?
cout << "str1 without all '___': " << ??
erase_all_copy( str1, "___" ) << endl; ?

// replace third and 5th occurrence of _ in str1 ?
// note that nth argument is 0-based ?
replace_nth( str1, "_", 4, "+" ); ?
replace_nth( str1, "_", 2, "+" ); ?

cout << "str1 with third and 5th occurrence of _ replace: " << str1 << endl; ?

// Custom formatter examples ?
string str2("abC-xxxx-AbC-xxxx-abc"); ?

// Find string 'abc' ignoring the case and convert it to upper case ?
cout << "Upcase all 'abc'(s) in the str2: " << ?
find_format_all_copy( ??
str2, ?
first_finder("abc", is_iequal()), ??
upcase_formatter ); ?

cout << endl; ?

return 0; ?
}
========

boost流的小例子

http://blog.sina.com.cn/s/blog_62b4e3ff0101amtv.html
標準流只能處理：標準輸入輸出(stdin,stdout，stderr),文件，字符串。
現在想用流的思想處理一個內存塊。將一個內存塊當做一個“設備”


//
//利用標準庫的stringstream處理
void Chapter1()
{
char data[100];
strcpy(data,"123 456 789"); //要處理的數組，當做一個內存塊
//我們不關心內存是從哪里來的，數據如何賦值上去的。


std::string str(data); ? ?//一次拷貝
std::stringstream ss(str);//二次拷貝


//缺點：1)數據多次拷貝。2)只能處理char(0)結束的“字符串”，不能處理更廣泛的“字符流”。


int x,y,z;
ss >> x >> y >> z ;


return 0;
}


/利用“小作坊”生產的“家釀”代碼
#include <streambuf>
#include <istream>


struct my_streambuf : public std::basic_streambuf
{
my_streambuf(char* buffer, std::streamsize length)
{
setg(buffer, buffer, buffer + length);
setp(buffer, buffer + length);
}
};


void Chapter2()
{
char data[100];
strcpy(data,"123 456 789");


my_streambuf buff(data,100); //流緩沖，負責對設備操作
std::istream iss(&buff); ? ? //標準流，負責對用戶數據的格式化，非格式化處理。


int x,y,z;
iss >> x >> y >> z ;


return 0;
}


//
//利用boost.iostreams庫處理
#include <boost/iostreams/device/array.hpp>
#include <boost/iostreams/stream.hpp>
#include <iomanip>


void Chapter3()
{ ? ?
namespace io = boost::iostreams;


char buff[32]={0};
io::array one(buff,32);

//io::array 的身世
//別名 boost::iostreams::basic_array<char>?
//符合 概念<SeekableDevice> 精化于 {概念<Source>,概念<Sink>} 意味著：字符序列的來源，去向。
//具有 模式<Seekable> 意味著：可以隨意移動讀寫頭
//符合 概念<Direct> ? 意味著：不用文件緩存的那種機制。經過另一個buffer的緩沖是毫無必要的。

io::stream<io::array> s(one); ? ??


s << "hello" << ' ' << "world " << std::setw(4) << std::setfill('0') << 123 ?; //輸出


io::seek(s,0,std::ios_base::beg); //移動讀寫頭的位置


std::string s1,s2,s3;
s >> s1 >> s2 >> s3; ? ? //輸入

s.clear(); ?//復位標志位為ios_base::good。因為前面的操作遇到字符char(0)，將流狀態變成eof
io::seek(s,0,std::ios_base::beg);


char i;
for (i='a';s; ++i) //循環的寫任意多個字符，很快的就能遇到失敗。
//失敗的原因是：數組不是文件，只能寫數組定義時的最大值。
{ ? ? ? ? ? ? ? ? ?//即使是文件能自動增長，也有物理的最大限制。
s << i ;
if (!s) break;
}

char* pstr = "HELLO WORLD" ;
io::array another(pstr,strlen(pstr)); //定義另一個“數組”，作為一個新設備(Device)。


s.close(); //關閉舊Device
if (!s.is_open()){
s.open(another); //打開另一個Device
}


s >> s1 >> s2; //輸入


//s << 123 ? //不要嘗試它，pstr指向一個被寫保護的內存區，任何寫嘗試都會讓程序掛掉。


}
========

boost::filesystem遍歷目錄

http://blog.csdn.net/hhhbbb/article/details/6799564
#include <boost::filesystem.hpp>
using namespace boost::filesystem;
void file_executor::iterate_folder(const string full_path)
{


directory_iterator end;
for(directory_iterator pos(full_path);pos !=end; ++pos){
boost::filesystem::path path_(*pos);
if(is_regular(path_)){
string s= path_.string();
vector_files.push_back(s);
files_num ++;
}
else if(is_directory(path_)){
iterate_folder(path_.string());
}
}

}
========

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