c++的string类的模拟实现以及basic_string::_M_construct null not valid错误的原因-CSDN博客
C++ : How to fix 'std::logic_error' what(): basic_string::_M_construct null not valid error? - YouTube
terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid Aborted (core dumped) : r/cpp_questions