"you shouldn't use a default argument as a flag upon which to conditionallly execute code. you should instead break the function into two or more overloaded functions" (查看原文)
But, and this is an important point, as soon as you decide to write your own copy-constructor and assignment operator, the compiler assumes that you know what you’re doing and does not automatically call the base-class versions, as it does in the synthesized functions. If you want the base class versions called (and you typically do) then you must explicitly call them yourself. (查看原文)
$ g++ c12TypeConversation.cpp
c12TypeConversation.cpp: 在函数‘int main()’中:
c12TypeConversation.cpp:48:20: 错误： 对‘Person::Person(Person)’的调用没有匹配的函数
c12TypeConversation.cpp:48:20: 附注： 备选是：
c12TypeConversation.cpp:19:5: 附注： Person::Person(const char*)
c12TypeConversation.cpp:19:5: 附注： no known conversion for argument 1 from ‘Person’ to ‘const char*’
c12TypeConversation.cpp:9:5: 附注： Person::Person(Person&)
c12TypeConversation.cpp:9:5: 附注： no known conversion for argument 1 from ‘Person’ to ‘Person&’
c12TypeConversation.cpp:39:6: 错误： 初始化‘void whatname(Person)’的实参 1 (查看原文)
