c++返回指针的函数，想引用老是报错

Question

#include
#include
using namespace std;
char *subString(char *s, int start, int end);
int main()
{
string s;
s="we are the world";
subString(&s,5,10);
return 0;
}

char *subString(char *s, int start, int end)
{
int len = strlen(s);
if (start < 0 || start >= len || end < 0 ||
end >= len || start > end) {
cout << "起始或终止位置错" << endl;
return NULL;
}
char *sub = new char[end - start + 2];
strncpy(sub, s + start, end - start +1);
sub[end - start +1] = '\0';
return sub;
}

一直报错C:\Users\dell\Desktop\指针问题二.cpp|9|error: cannot convert 'std::__cxx11::string* {aka std::__cxx11::basic_string}' to 'char' for argument '1' to 'char* subString(char*, int, int)'|

Answer 1

subString(&s,5,10);
--》
 subString((char *)s.data(),5,10);