C/C中的mbsinit（）函数++-yiteyi-C++库

这个 mbsinit（） 是C++中的一个内置函数，用来检查是否附言（作为参数传递到此函数）指向描述初始转换状态的mbstate_t对象。对于表示初始状态的任何mbstate_t对象，或者如果ps是空指针，此函数将返回非零。 ps指向的状态可以通过调用以下命令设置为初始状态：

null

// ps points now to a zero-valued objectmemset (ps, 0, sizeof(*ps));

语法：

int mbsinit( const mbstate_t* ps)

参数： 该函数接受一个参数，如下所述：

附言： 指向mbstate_t对象的指针

返回值： 函数返回两个值，如下所示：

如果ps不是空指针且不代表初始转换状态，则为0。
如果ps是空指针或表示初始转换状态，则为非零。

以下程序说明了上述功能： 项目1：

CPP

                         // C++ program to illustrate                       
                         // mbsinit() function                       
           
                         #include <bits/stdc++.h>                       
                         using                                     namespace                                     std;                       
           
                         // function to check if the object describes                       
                         // the initial conversion state                       
                         void                                     checkfor(                                     mbstate_t                                     ps)                       
                         {                       
                                                 // (mbstate_t) Type that holds the information necessary                       
                                                 // to maintain the state when converting between                       
                                                 // sequences of multibyte characters and                       
                                                 // wide characters (either way).                       
           
                                                 int                                     func = mbsinit(&ps);                       
           
                                                 if                                     (func)                       
                                                 cout<<                                     "The conversion state is initial"                       
                                                 <<                                     " conversion state"                                     ;                       
           
                                                 else                       
                                                 cout<<                                     "The conversion state is not initial"                       
                                                 <<                                     " conversion state"                                     ;                       
                         }                       
           
                         // Driver code                       
                         int                                     main()                       
                         {                       
                                                 setlocale                                     (LC_ALL,                                     "en_US.utf8"                                     );                       
           
                                                 // initializing the string                       
                                                 char                                     str[] =                                     "u00df"                                     ;                       
           
                                                 // initial state                       
                                                 mbstate_t                                     ps =                                     mbstate_t                                     ();                       
           
                                                 // check if ps is liknked to                       
                                                 // initial conversion state                       
                                                 checkfor(ps);                       
           
                                                 mbrlen(str, 1, &ps);                       
           
                                                 // check if, after getting the                       
                                                 // length of multibyte character                       
                                                 checkfor(ps);                       
           
                                                 return                                     0;                       
                         }                       

输出：

The conversion state is initial conversion stateThe conversion state is not initial conversion state

项目2：

CPP

                         // C++ program to illustrate                       
                         // mbsinit() function                       
                         // with empty string                       
           
                         #include <bits/stdc++.h>                       
                         using                                     namespace                                     std;                       
           
                         // function to check if                       
                         // object describes the initial conversion state                       
                         void                                     checkfor(                                     mbstate_t                                     ps)                       
                         {                       
                                                 // (mbstate_t) Type that holds the information necessary                       
                                                 // to maintain the state when converting between                       
                                                 // sequences of multibyte characters and                       
                                                 // wide characters (either way).                       
           
                                                 int                                     func = mbsinit(&ps);                       
           
                                                 if                                     (func)                       
                                                 cout <<                                     "the conversion state is initial"                       
                                                 <<                                     " conversion state"                                     ;                       
           
                                                 else                       
                                                 cout <<                                     "the conversion state is not initial"                       
                                                 <<                                     " conversion state"                                     ;                       
                         }                       
           
                         // Driver code                       
                         int                                     main()                       
                         {                       
                                                 setlocale                                     (LC_ALL,                                     "en_US.utf8"                                     );                       
           
                                                 // initializing the string                       
                                                 char                                     str[] =                                     ""                                     ;                       
           
                                                 // initial state                       
                                                 mbstate_t                                     ps =                                     mbstate_t                                     ();                       
           
                                                 // check if ps is liknked to                       
                                                 // initial conversion state                       
                                                 cout <<                                     "After ps is initialized, "                                     ;                       
                                                 checkfor(ps);                       
           
                                                 mbrlen(str, 0, &ps);                       
           
                                                 // check if, after getting the                       
                                                 // length of multibyte character                       
                                                 cout <<                                     "After performing some task, "                                     ;                       
                                                 checkfor(ps);                       
           
                                                 return                                     0;                       
                         }                       

输出：

After ps is initialized, the conversion state is initial conversion stateAfter performing some task, the conversion state is initial conversion state

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