无法逆向操作。 错误说它不能将 void 转换为字符串，但我的结果保存为字符串。 已显示代码以供参考

Question

string result;
for(int i=st.size()-1;i>=0;i--){
 result+=st.top();
 cout<<st.top()<<endl;
 st.pop();}
 result+='\0';
 return reverse(result.begin(), result.end());

st is a stack of character. I want to output stack elements in reverse order

Answer 1

The return value of std::reverse() is void , so you can't return it (except from a function that itself returns void ).

std:reverse() modifies the contents of the input range inline, so just return the std::string variable whose characters you are asking std::reverse() to modify, eg:

string result;
while (!st.empty()){
    result += st.top();
    cout << st.top() << endl;
    st.pop();
}
reverse(result.begin(), result.end());
return result; // <-- here

Alternatively, you could just use string::insert() instead and not use std::reverse() at all, eg:

string result;
result.reserve(st.size());
while (!st.empty()){
    result.insert(0, st.top());
    cout << st.top() << endl;
    st.pop();
}
return result;