运行时提示错误basic_string::_S_construct null not valid

代码

char* xxx = func();

string yyy(xxx);

运行时提示错误：

terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_S_construct null not valid

提示的错误已经很明确，是string构造不能传入空指针xxx，即在xxx为空时会报上面错误，保证func返回不为空即可。