Class member functions can directly access the private variables of the class parameters.

I was reading "C ++ meditation" just now and had doubts about the following code:

Class vehicelsurrogate {<br/> Public: <br/> //.... <br/> vehiclesurrogate (const vehicelsurrogate &); <br/> //.... <br/> PRIVATE: <br/> vehicle * VP; <br/>}; <br/> vehicelsurrogate: vehicelsurrogate <br/> (const vehicelsurrogate & V ): <br/> VP (v. VP? V. VP-> copy (): 0 ){}

Previously, the member functions defined in this class must be used to access the class parameters. However, in the preceding example, the parameter V directly accesses its private variables. To verify whether this writing method is feasible, write a small program for verification. The procedure is as follows:

/* <Br/> * file: scope. CPP <br/> */<br/> class int {<br/> Public: <br/> int (): Value (0) {}< br/> int (INT Val): Value (VAL) {}< br/> int (const Int & X); <br/> ~ INT () {}</P> <p> Int & operator = (const Int & X); <br/> PRIVATE: <br/> int value; <br/>}; <br/> INT: int (const Int & X) <br/>{< br/> value = x. value; <br/>}< br/> Int & INT: Operator = (const Int & X) <br/>{< br/> If (this! = & X) <br/> value = x. value; <br/> return * This; <br/>}< br/> int main () <br/>{< br/> int A (1 ); <br/> int B; <br/> B = A; <br/>}< br/>

Compile, run, and Debug:

Supertool @ supertool-desktop :~ /Test $ C ++-wall-G scope. cpp-O scope <br/> supertool @ supertool-desktop :~ /Test $./scope <br/> supertool @ supertool-desktop :~ /Test $ GDB. /scope <br/> gnu gdb (GDB) 7.1-ubuntu <br/> copyright (c) 2010 Free Software Foundation, Inc. <br/> license gplv3 +: gnu gpl Version 3 or later <pttp://gnu.org/licenses/gpl.html> <br/> This is free software: You are free to change and redistribute it. <br/> there is no warranty, to the extent permitted by law. type "show copying" <br/> and "show warranty" for details. <br/> This GDB was configu Red as "x86_64-linux-gnu ". <br/> for Bug reporting instructions, please see: <br/> <pttp://www.gnu.org/software/gdb/bugs/>... <br/> reading symbols from/home/supertool/test/scope... done. <br/> (GDB) L <br/> 20int & INT: Operator = (const Int & X) <br/> 21 {<br/> 22if (this! = & X) <br/> 23 value = x. value; <br/> 24 return * This; <br/> 25} <br/> 26 <br/> 27int main () <br/> 28 {<br/> 29int A (1); <br/> (GDB) L <br/> 30int B; <br/> 31 <br/> 32B = A; <br/> 33} <br/> (GDB) B 32 <br/> breakpoint 1 at 0x400635: file Scope. CPP, line 32. <br/> (GDB) r <br/> starting program:/home/supertool/test/scope <br/> breakpoint 1, main () at scope. CPP: 32 <br/> 32B = A; <br/> (GDB) S <br/> INT: Operator = (this = 0x7fffffffe230, x =...) at scope. cpp: 22 <br/> 22if (this! = & X) <br/> (GDB) S <br/> 23 value = x. value; <br/> (GDB) print value <br/> $1 = 0 <br/> (GDB) print X. value <br/> $2 = 1 <br/> (GDB) n <br/> 24 return * This; <br/> (GDB) print this <br/> $3 = (int * const) 0x7fffffffe230 <br/> (GDB) print * $3 <br/> $4 = {value = 1} <br/> (GDB) <br/>

Through the above program verification, this writing method is feasible. At least no error is reported in my editor. Here, we may confuse the above situation with the conventions that the subclass can only access the parent class and protect members. Further research is required.