boost库的常用组件的使用(ZT)-白红宇

1.boost::any

boost::any是一种通用的数据类型，可以将各种类型包装后统一放入容器内

最重要的它是类型安全的。有点象COM里面的variant.

使用方法：

any::type() 返回包装的类型

any_cast可用于any到其他类型的转化

#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仅仅是对数组一层薄薄的封装，提供跟各种算法配合的iterator,使用方法很简单

注意：可以使用{}来初始化array,因为array所有的成员变量都是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用于将字符串转换成各种数字类型(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，优点是类型安全，不会因为类型和参数不匹配而导致程序崩溃了

而且还可以重复使用参数

#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，类似于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 << " \n " ;

}

6.boost::thread

boost::thread是为了提供跨平台的thread机制。利用boost::function来完成委托。

#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。而且提供好几种序列化的格式，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\n " ;

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就是所谓的泛函数，能够对普通函数指针，成员函数指针，functor进行委托，达到迟调用的效果

#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就是智能指针的实现，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()));

}