// 1 filename:cpp2011-7-3-4.cpp
// ver 0.1 June.13, 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
// > 7 Declarations 7.3 Namespaces 7.3.4 Using directive
//
// 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 cpp2011-7-3-4.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 cpp2011-7-3-4.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>

using namespace std;

namespace A {
int i;
namespace B {
namespace C {
int i;
}
using namespace A::B::C;
void f1() {
i = 5; // OK, C::i visible in B and hides A::i
}
}
namespace D {
using namespace B;
using namespace C;
void f2() {
//error: i = 5; // ambiguous, B::C::i or A::i?
}
}
void f3() {
i = 5; // uses A::i
}
}
void f4() {
	//error: i = 5; // ill-formed; neither i is visible
}
//
namespace M {
int i;
}
namespace N {
int i;
using namespace M;
}
void f() {
using namespace N;
	//error: i = 7; // error: both M::i and N::i are visible
}	
namespace A {
int i2;
}
namespace B {
int i2;
int j;
namespace C {
namespace D {
using namespace A;
int j;
int k;
int a = i2; // B::i hides A::i
}
using namespace D;
int k = 89; // no problem yet
		//error: int l = k; // ambiguous: C::k or D::k
int m = i2; // B::i hides A::i
int n = j; // D::j hides B::j
}
}
//
namespace A {
class X { };
extern "C" int g();
extern "C++" int h();
}
namespace B {
void X(int);
extern "C" int g();
extern "C++" int h(int);
}
using namespace A;
using namespace B;
void f2() {
X(1); // error: name X found in two namespaces
g(); // okay: name g refers to the same entity
h(); // okay: overload resolution selects A::h
}
//
namespace D {
int d1;
void f4(char);
}
using namespace D;
int d1; // OK: no conflict with D::d1
namespace E {
int e;
void f4(int);
}
namespace D { // namespace extension
int d2;
using namespace E;
void f4(int);
}
void f4() {
d1++; // error: ambiguous ::d1 or D::d1?
::d1++; // OK
D::d1++; // OK
d2++; // OK: D::d2
e++; // OK: E::e
//error: f(1); // error: ambiguous: D::f(int) or E::f(int)?
f4('a'); // OK: D::f(char)
}

int main() {
	//
	cout << f4 << std::endl;
	cout << "7 Declarations 7.3 Namespaces 7.3.4 Using directive" << std::endl;
	return 0;
}
// 1 error
// 1.1 c++ -std=c++11 -stdlib=libc++ -Wall cpp2011-7-3-4.cpp 
cpp2011-7-3-4.cpp:140:17: error: reference to 'B' is ambiguous
using namespace B;
                ^
cpp2011-7-3-4.cpp:134:11: note: candidate found by name lookup is 'B'
namespace B {
          ^
cpp2011-7-3-4.cpp:73:11: note: candidate found by name lookup is 'A::B'
namespace B {
          ^
cpp2011-7-3-4.cpp:142:1: error: no matching conversion for functional-style cast from 'int' to 'A::X'
X(1); // error: name X found in two namespaces
^~~
cpp2011-7-3-4.cpp:130:7: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const A::X' for 1st
      argument
class X { };
      ^
cpp2011-7-3-4.cpp:130:7: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'int' to 'A::X' for 1st argument
class X { };
      ^
cpp2011-7-3-4.cpp:130:7: note: candidate constructor (the implicit default constructor) not viable: requires 0 arguments, but 1 was provided
cpp2011-7-3-4.cpp:151:17: error: reference to 'D' is ambiguous
using namespace D;
                ^
cpp2011-7-3-4.cpp:147:11: note: candidate found by name lookup is 'D'
namespace D {
          ^
cpp2011-7-3-4.cpp:82:11: note: candidate found by name lookup is 'A::D'
namespace D {
          ^
cpp2011-7-3-4.cpp:162:6: error: redefinition of 'f4'
void f4() {
     ^
cpp2011-7-3-4.cpp:93:6: note: previous definition is here
void f4() {
     ^
cpp2011-7-3-4.cpp:165:1: error: expected a class or namespace
D::d1++; // OK
^
cpp2011-7-3-4.cpp:165:1: error: reference to 'D' is ambiguous
D::d1++; // OK
^
cpp2011-7-3-4.cpp:157:11: note: candidate found by name lookup is 'D'
namespace D { // namespace extension
          ^
cpp2011-7-3-4.cpp:82:11: note: candidate found by name lookup is 'A::D'
namespace D {
          ^
cpp2011-7-3-4.cpp:166:1: error: use of undeclared identifier 'd2'; did you mean 'D::d2'?
d2++; // OK: D::d2
^~
D::d2
cpp2011-7-3-4.cpp:158:5: note: 'D::d2' declared here
int d2;
    ^
cpp2011-7-3-4.cpp:167:1: error: use of undeclared identifier 'e'; did you mean 'D::e'?
e++; // OK: E::e
^
D::e
cpp2011-7-3-4.cpp:154:5: note: 'D::e' declared here
int e;
    ^
cpp2011-7-3-4.cpp:169:1: error: no matching function for call to 'f4'
f4('a'); // OK: D::f(char)
^~
cpp2011-7-3-4.cpp:162:6: note: candidate function not viable: requires 0 arguments, but 1 was provided
void f4() {
     ^
9 errors generated.