[libcxx] r269789 - Implement LWG2576: istream_iterator and ostream_iterator should use std::addressof
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue May 17 14:22:47 PDT 2016
Here's an istream_iterator test for this change:
#include <sstream>
#include <iterator>
#include <cassert>
struct evil_traits : std::char_traits<char> {
template<typename T> friend void operator&(T) = delete;
};
struct pointless_derived_class
: std::num_get<char, std::istreambuf_iterator<char, evil_traits>> {};
int main() {
std::basic_stringstream<char, evil_traits> ss("1 2 3");
ss.imbue(std::locale(ss.getloc(), new pointless_derived_class));
using II = std::istream_iterator<int, char, evil_traits>;
int n = 0;
for (auto i = II(ss), e = II(); i != e; ++i)
n += *i;
assert(n == 6);
}
PS: locales suck.
On Tue, May 17, 2016 at 2:09 PM, Eric Fiselier via cfe-commits <
cfe-commits at lists.llvm.org> wrote:
> OK, I think I figured it out. I added tests for the ostream_iterator
> constructors in r269838.
> I'll follow that up with tests for the istream_iterator constructors, but
> my current test is failing for reasons beyond me.
>
> /Eric
>
> On Tue, May 17, 2016 at 2:36 PM, Eric Fiselier <eric at efcs.ca> wrote:
>
>> Or maybe I'm still wrong. I tried using a custom traits class to hijack
>> ADL for "operator&" but it doesn't seem to work.
>>
>> Sorry for the spam.
>>
>> /Eric
>>
>> On Tue, May 17, 2016 at 2:25 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>
>>> Woops. I was incorrect. It seems that user defined "operator&" overloads
>>> can be found in the constructor. From the LWG issue:
>>>
>>> > Note that {i,o}stream_type are specializations of basic_{i,o}stream,
>>> but the constructors might still pick up an overloaded & via the traits
>>> template parameter.
>>>
>>> At least that also tells us how to test it.
>>>
>>> /Eric
>>>
>>> On Tue, May 17, 2016 at 2:08 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>>
>>>> The difference between "operator&" and "addressof" is inconsequential
>>>> when user defined overloads of "operator&" can't be found, which is the
>>>> case for the changes in the stream iterator constructors. We might as well
>>>> keep it consistent though. I don't see any value changing it back to use
>>>> "operator&" in either the library or the standard.
>>>>
>>>> /Eric
>>>>
>>>> On Tue, May 17, 2016 at 2:02 PM, David Blaikie <dblaikie at gmail.com>
>>>> wrote:
>>>>
>>>>> If some parts are not testable & as you say, not meaningful, then it
>>>>> seems OK to just not implement them & file a DR on the standard, no?
>>>>>
>>>>> On Tue, May 17, 2016 at 1:00 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>>>>
>>>>>> I added a test for operator->() in r269812. Marshall and I discussed
>>>>>> offline about how not all parts of this change are testable (and hence not
>>>>>> meaningful) but that's what the standard says to do.
>>>>>>
>>>>>>
>>>>>> On Tue, May 17, 2016 at 1:51 PM, David Blaikie via cfe-commits <
>>>>>> cfe-commits at lists.llvm.org> wrote:
>>>>>>
>>>>>>> Test coverage?
>>>>>>>
>>>>>>> On Tue, May 17, 2016 at 10:44 AM, Marshall Clow via cfe-commits <
>>>>>>> cfe-commits at lists.llvm.org> wrote:
>>>>>>>
>>>>>>>> Author: marshall
>>>>>>>> Date: Tue May 17 12:44:40 2016
>>>>>>>> New Revision: 269789
>>>>>>>>
>>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=269789&view=rev
>>>>>>>> Log:
>>>>>>>> Implement LWG2576: istream_iterator and ostream_iterator should use
>>>>>>>> std::addressof
>>>>>>>>
>>>>>>>> Modified:
>>>>>>>> libcxx/trunk/include/iterator
>>>>>>>> libcxx/trunk/www/cxx1z_status.html
>>>>>>>>
>>>>>>>> Modified: libcxx/trunk/include/iterator
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/iterator?rev=269789&r1=269788&r2=269789&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- libcxx/trunk/include/iterator (original)
>>>>>>>> +++ libcxx/trunk/include/iterator Tue May 17 12:44:40 2016
>>>>>>>> @@ -772,14 +772,14 @@ private:
>>>>>>>> _Tp __value_;
>>>>>>>> public:
>>>>>>>> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator()
>>>>>>>> : __in_stream_(0), __value_() {}
>>>>>>>> - _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s)
>>>>>>>> : __in_stream_(&__s)
>>>>>>>> + _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s)
>>>>>>>> : __in_stream_(_VSTD::addressof(__s))
>>>>>>>> {
>>>>>>>> if (!(*__in_stream_ >> __value_))
>>>>>>>> __in_stream_ = 0;
>>>>>>>> }
>>>>>>>>
>>>>>>>> _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return
>>>>>>>> __value_;}
>>>>>>>> - _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const
>>>>>>>> {return &(operator*());}
>>>>>>>> + _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const
>>>>>>>> {return _VSTD::addressof((operator*()));}
>>>>>>>> _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
>>>>>>>> {
>>>>>>>> if (!(*__in_stream_ >> __value_))
>>>>>>>> @@ -811,9 +811,9 @@ private:
>>>>>>>> const char_type* __delim_;
>>>>>>>> public:
>>>>>>>> _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s)
>>>>>>>> - : __out_stream_(&__s), __delim_(0) {}
>>>>>>>> + : __out_stream_(_VSTD::addressof(__s)), __delim_(0) {}
>>>>>>>> _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s,
>>>>>>>> const _CharT* __delimiter)
>>>>>>>> - : __out_stream_(&__s), __delim_(__delimiter) {}
>>>>>>>> + : __out_stream_(_VSTD::addressof(__s)),
>>>>>>>> __delim_(__delimiter) {}
>>>>>>>> _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const
>>>>>>>> _Tp& __value_)
>>>>>>>> {
>>>>>>>> *__out_stream_ << __value_;
>>>>>>>>
>>>>>>>> Modified: libcxx/trunk/www/cxx1z_status.html
>>>>>>>> URL:
>>>>>>>> http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/cxx1z_status.html?rev=269789&r1=269788&r2=269789&view=diff
>>>>>>>>
>>>>>>>> ==============================================================================
>>>>>>>> --- libcxx/trunk/www/cxx1z_status.html (original)
>>>>>>>> +++ libcxx/trunk/www/cxx1z_status.html Tue May 17 12:44:40 2016
>>>>>>>> @@ -222,7 +222,7 @@
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2572">2572</a></td><td>The
>>>>>>>> remarks for <tt>shared_ptr::operator*</tt> should apply to
>>>>>>>> <i>cv</i>-qualified <tt>void</tt> as
>>>>>>>> well</td><td>Jacksonville</td><td>Complete</td></tr>
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2574">2574</a></td><td>[fund.ts.v2]
>>>>>>>> <tt>std::experimental::function::operator=(F&&)</tt> should be
>>>>>>>> constrained</td><td>Jacksonville</td><td></td></tr>
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2575">2575</a></td><td>[fund.ts.v2]
>>>>>>>> <tt>experimental::function::assign</tt> should be
>>>>>>>> removed</td><td>Jacksonville</td><td></td></tr>
>>>>>>>> - <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2576">2576</a></td><td><tt>istream_iterator</tt>
>>>>>>>> and <tt>ostream_iterator</tt> should use
>>>>>>>> <tt>std::addressof</tt></td><td>Jacksonville</td><td></td></tr>
>>>>>>>> + <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2576">2576</a></td><td><tt>istream_iterator</tt>
>>>>>>>> and <tt>ostream_iterator</tt> should use
>>>>>>>> <tt>std::addressof</tt></td><td>Jacksonville</td><td>Complete</td></tr>
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2577">2577</a></td><td><tt>{shared,unique}_lock</tt>
>>>>>>>> should use
>>>>>>>> <tt>std::addressof</tt></td><td>Jacksonville</td><td>Complete</td></tr>
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2579">2579</a></td><td>Inconsistency
>>>>>>>> wrt Allocators in <tt>basic_string</tt> assignment vs.
>>>>>>>> <tt>basic_string::assign</tt></td><td>Jacksonville</td><td>Complete</td></tr>
>>>>>>>> <tr><td><a href="
>>>>>>>> http://cplusplus.github.io/LWG/lwg-defects.html#2581">2581</a></td><td>Specialization
>>>>>>>> of <tt><type_traits></tt> variable templates should be
>>>>>>>> prohibited</td><td>Jacksonville</td><td>Complete</td></tr>
>>>>>>>>
>>>>>>>>
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>>>>>>>>
>>>>>>>
>>>>>>>
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>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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