Ray's playground

摘要： Private inheritance means is-implemented-in-terms of. It's usually inferior to composition, but it makes sense when a derived class needs access to protected base class members or needs to redefine inherited virtual functions. Unlike composition, private inheritance can enable the empty base opt 阅读全文

摘要： Composition has meanings completely different from that of public inheritance. In the application domain, composition means has-a. In the implementation domain, it means is-implemented-in-terms-of. 阅读全文

摘要： 1#include<iostream>2#include<vector>3#include<string>4usingnamespacestd;56intmain()7{8constchar*p="hello";9intcount=0;10while(*p)11{12cout<<*p<<endl;13count++;14p++;15}1617constcharca[]={'h','e','l','l','o'};18constchar* 阅读全文

摘要： Never redefine an inherited default parameter value, because default parameter values are statically bound, while virtual functions — the only functions you should be overriding — are dynamically bound.1#include<iostream>2#include<string>3usingnamespacestd;45classShape6{7public:8virtualv 阅读全文

摘要： Never redefine an inherited non-virtual function. 阅读全文

摘要： The fundamental advice of this Item is to consider alternatives to virtual functions when searching for a design for the problem you're trying to solve. Here's a quick recap the alternatives we examined: Use the non-virtual interface idiom (NVI idiom), a form of the Template Method design pa 阅读全文

摘要： The ability to halt a process that is being debugged is achieved by settingbreakpoints. By halting the process, you are able to inspect variables, stackarguments, and memory locations without the process changing any of theirvalues before you can record them. Breakpoints are most definitely the mos. 阅读全文

摘要： 1>>>fromctypesimport*2>>>c_int()3c_long(0)4>>>c_char_p("helloworld!")5c_char_p('helloworld!')6>>>c_ushort(-5)7c_ushort(65531)8>>>seitz=c_char_p("lovespython")9>>>printseitz10c_char_p('lovespython')11>>> 阅读全文

摘要： Inheritance of interface is different from inheritance of implementation. Under public inheritance, derived classes always inherit base class interfaces. Pure virtual functions specify inheritance of interface only. Simple (impure) virtual functions specify inheritance of interface plus inheritance. 阅读全文

摘要： 1#import"MyDocument.h"2#import"DepartmentViewController.h"3#import"EmployeeViewController.h"45@implementationMyDocument67-(id)init8{9[superinit];10viewControllers=[[NSMutableArrayalloc]init];1112ManagingViewController*vc=[[DepartmentViewControlleralloc]init];13[vcsetMan 阅读全文