//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <array>

// iterator begin();

#include <array>
#include <cassert>

#include "test_macros.h"

// std::array is explicitly allowed to be initialized with A a = { init-list };.
// Disable the missing braces warning for this reason.
#include "disable_missing_braces_warning.h"

struct NoDefault {
  NoDefault(int) {}
};


int main()
{
    {
        typedef double T;
        typedef std::array<T, 3> C;
        C c = {1, 2, 3.5};
        C::iterator i;
        i = c.begin();
        assert(*i == 1);
        assert(&*i == c.data());
        *i = 5.5;
        assert(c[0] == 5.5);
    }
    {
      typedef NoDefault T;
      typedef std::array<T, 0> C;
      C c = {};
      C::iterator ib, ie;
      ib = c.begin();
      ie = c.end();
      assert(ib == ie);
      LIBCPP_ASSERT(ib != nullptr);
      LIBCPP_ASSERT(ie != nullptr);
    }
}

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <array>

// iterator begin();

#include <array>
#include <cassert>

// std::array is explicitly allowed to be initialized with A a = { init-list };.
// Disable the missing braces warning for this reason.
#include "disable_missing_braces_warning.h"

struct NoDefault {
  NoDefault(int) {}
};


int main()
{
    {
        typedef double T;
        typedef std::array<T, 3> C;
        C c = {1, 2, 3.5};
        C::iterator i;
        i = c.begin();
        assert(*i == 1);
        assert(&*i == c.data());
        *i = 5.5;
        assert(c[0] == 5.5);
    }
    {
      typedef NoDefault T;
      typedef std::array<T, 0> C;
      C c = {};
      assert(c.begin() == c.end());
    }
}

--- 
+++ 
@@ -13,6 +13,8 @@
 
 #include <array>
 #include <cassert>
+
+#include "test_macros.h"
 
 // std::array is explicitly allowed to be initialized with A a = { init-list };.
 // Disable the missing braces warning for this reason.
@@ -40,6 +42,11 @@
       typedef NoDefault T;
       typedef std::array<T, 0> C;
       C c = {};
-      assert(c.begin() == c.end());
+      C::iterator ib, ie;
+      ib = c.begin();
+      ie = c.end();
+      assert(ib == ie);
+      LIBCPP_ASSERT(ib != nullptr);
+      LIBCPP_ASSERT(ie != nullptr);
     }
 }
[libcxx] Add checks for unique value of array<T, 0>.begin() and array<T, 0>.end()

The standard section [array.zero] requires the return value of begin()
and end() methods of a zero-sized array to be unique. Eric Fiselier
clarifies: "That unique value cannot be null, and must be properly aligned".
This patch adds checks for the first part of this clarification: unique
value returned by these methods cannot be null.

Reviewed as https://reviews.llvm.org/D55366.
Thanks to Andrey Maksimov for the patch.

git-svn-id: 756ef344af921d95d562d9e9f9389127a89a6314@348509 91177308-0d34-0410-b5e6-96231b3b80d8
