Universal converter boost: lexical_cast

Boost: lexical_cast is a conversion between values. For example, to convert a string "123" to an integer 123, the Code is as follows:

 
 

  
  
string s = "123";  
  
  
int a = lexical_cast<int>(s); 
 
 

This method is very simple. I strongly recommend that you forget many std functions and directly use boost: lexical_cast. If the conversion happens unexpectedly, lexical_cast will throw a bad_lexical_cast exception, so it needs to be captured in the program.

Now you can write the following program to experience how to use boost: lexical_cast to complete numerical conversion. Program 4-11: Use boost: lexical_cast to convert object values

 
 

  
  
01  #include "stdafx.h" 
  
  
02    
  
  
03  #include <iostream>  
  
  
04  #include <boost/lexical_cast.hpp>  
  
  
05    
  
  
06  using namespace std;  
  
  
07  using namespace boost;  
  
  
08    
  
  
09  int main()  
  
  
10  {  
  
  
11      string s = "123";  
  
  
12      int a = lexical_cast<int>(s);  
  
  
13      double b = lexical_cast<double>(s);  
  
  
14    
  
  
15      printf("%d\r\n", a + 1);  
  
  
16      printf("%lf\r\n", b + 1);  
  
  
17    
  
  
18      try 
  
  
19      {  
  
  
20          int c = lexical_cast<int>("wrong number");  
  
  
21      }  
  
  
22      catch(bad_lexical_cast & e)  
  
  
23      {  
  
  
24          printf("%s\r\n", e.what());  
  
  
25      }  
  
  
26    
  
  
27      return 0;28 } 
 
 

The above program implements the conversion from a string "123" to an integer and a double-precision real number. To prevent program cheating, we specifically asked it to add the value to 1), and the output result is 4-19.

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Click to view the big picture.) Figure 4-19 shows the running result.

This project corresponds to the "\ ch04 \ LexicalCastTest" directory in the CD ". ================================ 650) this. width = 650; "onclick = 'window. open ("http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'alt =" "src =" http://book.vcer.net/images/vcmap-s.gif "/> the above is taken from section 4.6.2 of the VC ++.

This article is from the "Bai Qiao blog" blog, please be sure to keep this source http://bluejoe.blog.51cto.com/807902/193411