terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_S_construct

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

 

主要原因：string对一个空指针进行操作。

 

例如：char* p = NULL:

string str(p);              //运行时报错