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2014/06/16

C++N3242, 2011(111) 11.4 Protected member access

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// 1 filename:cpp2011-11-4.cpp
// ver 0.1 June.15, 2014
//
// 2 original examples and/or notes:
// (c) ISO/IEC JTC1 SC22 WG21 N3242, April 12, 2011
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
// > 11 Member access control 11.4 Protected member access
//
// 3 compile and output mechanism:
// (c) Dr. OGAWA Kiyoshi, kaizen at gifu-u.ac.jp,
//
// 4 compile errors and/or warnings:
// 4.1(c) Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
// Target: x86_64-apple-darwin13.2.0,  Thread model: posix
// Command/Options: c++ -std=c++11 -stdlib=libc++ -Wall cpp2011-11-4.cpp 
// (c) LLVM 2003-2009 University of Illinois at Urbana-Champaign.

// 4.2. g++-4.9 (GCC) 4.9.0 20131229 (experimental)
// Copyright (C) 2013 Free Software Foundation, Inc.
// This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// http://gcc.gnu.org/onlinedocs/gcc/Standards.html
// Command/Options: g++-4.9  -std=c++11  -Wall cpp2011-11-4.cpp 
// g++-4.9: error: unrecognized command line option '-stdlib=libc++'
// Configuration:brew install gcc49
//
// 4.3. Visual Studio Express 2013, 
// (c) Microsoft http://www.visualstudio.com/
// SPEC:
// Windows 7, .NET Framework
// (c) VMware, Inc.
// VMWare fusion 6
//
// 5. Hardware:  MacBook Pro, 
//(c) Intel http://ark.intel.com/products/37006/
//Core 2 Duo 2.53GHz, 8GB, 1067MHz DDR3
//
// 6. Special Thanks: Upper organizatios and 
// ITSCJ/IPSJ http://www.itscj.ipsj.or.jp/itscj_english/index.html
// Renesas Electronics Corporation.http://www.renesas.com/
// NPO SESSAME project, http://www.sessame.jp/workinggroup/WorkingGroup3/
// Toyo Corporation, http://www.toyo.co.jp/English/
// Japan Standard Association, http://bit.ly/1lzykg1
// NPO TOPPERS project, https://www.toppers.jp/asp-d-download.html
// Daido Universcity, http://www.daido-it.ac.jp/gakubugakka/computer/index.html
// WITZ Co.Ltd., http://www.witz-inc.co.jp/products/solution/solution.html
// SevenWise.co., http://www.7ws.co.jp/index.html
// TOYOTA Motor Corporation, http://toyota.jp/
// IT planning Inc., http://www.itpl.co.jp/en/index.html
// DENSO Corporation, http://www.globaldenso.com/en/
// Aisin Seiki co. Ltd., http://www.aisin.com/
// Spancion Inc., http://www.spansion.com/
// Yazaki Corporation, http://www.yazaki-group.com/global/
// Pananosic Corporation, http://www.panasonic.net/
// SWEST: Summer Workshop on Embedded System Technologies , http://swest.toppers.jp
// CEST: Consortium for Embedded System Technology, http://www.ertl.jp/CEST/
// JUSE: Union of Japanese Scientists and Engineers, http://www.juse.or.jp/e/
// OSC:Open Source Conference, http://www.ospn.jp/

#include <iostream>
//#include <cstdlib>
//#include <string.h>
//#include <cstring>
//#include <type_traits>
//#include <cassert>
//#include <algorithm>
//#include <cmath>
//#include <complex>
//#include <cstddef>
//#include <new>
//#include <vector>

using namespace std;

class B {
protected:
int i;
static int j;
};
class D1 : public B {
};
class D2 : public B {
friend void fr(B*,D1*,D2*);
void mem(B*,D1*);
};
void fr(B* pb, D1* p1, D2* p2) {
//error: pb->i = 1; // ill-formed
//error: p1->i = 2; // ill-formed
p2->i = 3; // OK (access through a D2)
p2->B::i = 4; // OK (access through a D2, even though
// naming class is B)
//error: int B::* pmi_B = &B::i; // ill-formed
int B::* pmi_B2 = &D2::i; // OK (type of &D2::i is int B::*)
B::j = 5; // OK (because refers to static member)
D2::j = 6; // OK (because refers to static member)
}
void D2::mem(B* pb, D1* p1) {
//error: pb->i = 1; // ill-formed
//error: p1->i = 2; // ill-formed
i = 3; // OK (access through this)
B::i = 4; // OK (access through this, qualification ignored)
//error: int B::* pmi_B = &B::i; // ill-formed
int B::* pmi_B2 = &D2::i; // OK
j = 5; // OK (because j refers to static member)
B::j = 6; // OK (because B::j refers to static member)
}
void g(B* pb, D1* p1, D2* p2) {
//error: pb->i = 1; // ill-formed
//error: p1->i = 2; // ill-formed
//error: p2->i = 3; // ill-formed
}

int main() {

cout << "11 Member access control 11.4 Protected member access" << std::endl;
return 0;
}
// 1  error
//1.1 llvm:  c++ -std=c++11 -stdlib=libc++  -Wall cpp2011-11-4.cpp 
cpp2011-11-4.cpp:93:4: error: 'j' is a protected member of 'B'
B::j = 5; // OK (because refers to static member)
   ^
cpp2011-11-4.cpp:77:12: note: declared protected here
static int j;
           ^
cpp2011-11-4.cpp:102:10: warning: unused variable 'pmi_B2' [-Wunused-variable]
int B::* pmi_B2 = &D2::i; // OK
         ^
> 1 warning and 1 error generated.
//1.2 gcc: g++-4.9 -std=c++11 -Wall cpp2011-11-4.cpp 
cpp2011-11-4.cpp: In function 'void fr(B*, D1*, D2*)':
cpp2011-11-4.cpp:92:10: warning: unused variable 'pmi_B2' [-Wunused-variable]
 int B::* pmi_B2 = &D2::i; // OK (type of &D2::i is int B::*)
          ^
cpp2011-11-4.cpp: In member function 'void D2::mem(B*, D1*)':
cpp2011-11-4.cpp:102:10: warning: unused variable 'pmi_B2' [-Wunused-variable]
 int B::* pmi_B2 = &D2::i; // OK
          ^
Undefined symbols for architecture x86_64:
  "B::j", referenced from:
      fr(B*, D1*, D2*)  in cc2ILkK3.o
      D2::mem(B*, D1*)    in cc2ILkK3.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status

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