boost 常用

1.  类型转换

#include <boost/lexical_cast.hpp>

  string aa = boost::lexical_cast<string>(3);

double b = lexical_cast<double>("123.12");

*****

  int32_t a = 0;
  int8_t b=97;
  cout <<"a:" <<boost::lexical_cast<string>(a) <<"   ib:"<<boost::lexical_cast<string>(b) ;    ////a:0   ib:a
int8_t 被当作一个char在处理,97输出a

2.  格式化字符串

#include <boost/format.hpp>

string description_ = str(boost::format("用户%d 加入房间%s 失败") %receiverid % roomid_str );

string description_ = str(boost::format("用户%1% 加入房间%2% 失败") %receiverid % roomid_str );  %n% 表示第几个参数

string description_ = str(boost::format("用户[%1$5d] 加入房间%2% 失败") %receiverid % roomid_str ); [%1$5d] 表示第一个参数是整形，右对齐 5个字符扩充

3. 分隔字符串

 #include <boost/algorithm/string/split.hpp>
  #include <boost/algorithm/string/classification.hpp>
 vector<string> res;
 string str = "123$123$q%asdfsa";
  boost::split(res, str, boost::is_any_of( "$%" ));