[libcxx] r225375 - In C++03, a bunch of the arithmetic/logical/comparison functors (such as add/equal_to/logical_or) were defined as deriving from binary_funtion. That restriction was removed in C++11, but the tests still check for this. Change the test to look for the embedded types first_argument/second_argument/result_type. No change to the library, just more standards-compliant tests. Thanks to STL @ Microsoft for the suggestion.

[David Blaikie]

On Fri, Jan 9, 2015 at 3:56 PM, Marshall Clow <mclow.lists at gmail.com> wrote:

> On Jan 9, 2015, at 12:17 PM, David Blaikie <dblaikie at gmail.com> wrote:
>
> On Fri, Jan 9, 2015 at 11:35 AM, Marshall Clow <mclow.lists at gmail.com>
> wrote:
>
>>
>> On Jan 9, 2015, at 9:06 AM, David Blaikie <dblaikie at gmail.com> wrote:
>>
>>
>>
>> On Wed, Jan 7, 2015 at 12:31 PM, Marshall Clow <mclow.lists at gmail.com>
>> wrote:
>>
>>> Author: marshall
>>> Date: Wed Jan  7 14:31:06 2015
>>> New Revision: 225375
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=225375&view=rev
>>> Log:
>>> In C++03, a bunch of the arithmetic/logical/comparison functors (such as
>>> add/equal_to/logical_or) were defined as deriving from binary_funtion. That
>>> restriction was removed in C++11, but the tests still check for this.
>>> Change the test to look for the embedded types
>>> first_argument/second_argument/result_type. No change to the library, just
>>> more standards-compliant tests. Thanks to STL @ Microsoft for the
>>> suggestion.
>>>
>>
>> Are there any tests around to ensure the C++03 behavior remains in C++03?
>> Or is that not worth worrying about/preserving/implementing?
>>
>>
>> The tests will continue to pass if the functors are derived
>> from binary_function (which is how libc++ implements them).
>>
>
> Other than that, no.
>>
>> binary_function is an empty struct with three nested typedefs:
>>
>> template <class Arg1, class Arg2, class Result>
>> struct binary_function
>> {
>>     typedef Arg1   first_argument_type;
>>     typedef Arg2   second_argument_type;
>>     typedef Result result_type;
>> };
>>
>> The tests (now) check for the existence (and correctness) of
>> first_argument_type, second_argument_type and result_type.
>>
>> Right, what I mean is that if/when the functors no longer derive from
> binary_function, the tests would continue passing - not catching a
> regression for C++03, yes? (libc++ would no longer be a conforming
> implementation of C++03?)
>
>
> Yes, but when C++03 and C++11 differ, libc++ has consistently chosen the
> C++11 implementation.
>

Do they differ here, or does 11 just offer more flexibility (is the C++03
implementation a conforming C++11 implementation, or must the inheritance
be removed)

In any case, I think maybe I'm being unclear:

There's no test to ensure we don't regress the C++03 required behavior, now
that these tests have been generalized. It seems like that's a hole/should
be fixed?

- David


>
> — Marshall
>
>
>
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