促进C++中的ListalIa转换-yiteyi-C++库

促进LexicalCast在库“boost/lexical_cast.hpp”中定义，它提供了一个cast操作符boost:：lexical_cast，可以将数字从字符串转换为int或double等数字类型，反之亦然。

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词法_cast是诸如 std：：stoi（） , std：：stod（）和 std:：to_string（），它们被添加到C++11中的标准库中。现在让我们看看这个函数在程序中的实现。 例如：

Conversion
integer -> string
string- > integer
integer -> char
float- > string

相关例外情况： 如果转换失败，将抛出bad_词法_cast类型的异常，该异常派生自bad_cast。它抛出一个异常，因为float 52.50和字符串“geeksforgeks”无法转换为int类型的数字。

                     // CPP program to illustrate                   
                     // Boost.Lexical_Cast in C++                   
                     #include "boost/lexical_cast.hpp"                   
                     #include <bits/stdc++.h>                   
                     using                               namespace                               std;                   
                     using                               boost::lexical_cast;                   
                     using                               boost::bad_lexical_cast;                   
                     int                               main() {                   
                             
                                         // integer to string conversion                   
                                         int                               s = 23;                   
                                         string s1 = lexical_cast<string>(s);                   
                                         cout << s1 << endl;                   
                             
                                         // integer to char conversion                   
                                         array<                               char                               , 64> msg = lexical_cast<array<                               char                               , 64>>(45);                   
                                         cout << msg[0] << msg[1] << endl;                   
                             
                                         // string to integer conversion in integer value                   
                                         int                               num = lexical_cast<                               int                               >(                               "1234"                               );                   
                                         cout << num << endl;                   
                             
                                         // bad conversion float to int                   
                                         // using try and catch we display the error                   
                                         try                               {                   
                                         int                               num2 = lexical_cast<                               int                               >(                               "52.20"                               );                   
                                         }                   
                             
                                         // To catch exception                   
                                         catch                               (bad_lexical_cast &e) {                   
                                         cout <<                               "Exception caught : "                               << e.what() << endl;                   
                                         }                   
                             
                                         // bad conversion string to integer character                   
                                         // using tru and catch we display the error                   
                                         try                               {                   
                                         int                               i = lexical_cast<                               int                               >(                               "GeeksforGeeks"                               );                   
                                         }                   
                             
                                         // catching Exception                   
                                         catch                               (bad_lexical_cast &e) {                   
                                         cout <<                               "Exception caught :"                               << e.what() << endl;                   
                                         }                   
                             
                                         return                               0;                   
                     }                   

输出：-

23
45
1234
Exception caught : bad lexical cast: source type value could not be interpreted as target
Exception caught :bad lexical cast: source type value could not be interpreted as target

参考：- http://www.boost.org/

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