行为的封装

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct node{
    errno_t  (*fp_strcpy_s)(char * ,  rsize_t ,  const char * );
    size_t   (*fp_strlen)( const char * );
    int      (*fp_strcmp)( const char * ,  const char * );


}stringutil;
stringutil g_string={strcpy_s,strlen,strcmp};


int main(){
    char a[20];
    char b[10]="nihaodsd";
    printf("%d
",g_string.fp_strlen("nihao"));
    printf("%d
",g_string.fp_strcmp("aaa","aaa"));
    printf("%d
",g_string.fp_strcpy_s(a,g_string.fp_strlen(b)+1,b));

    printf("%s
",a);
    return 0;

}