Mods to search_n test to show msvc failure

[Jim Bell <jim@…>]

The range trunk test matrix shows a couple stray failures for msvc tests. As you probably suspect, the problem seems to be in msvc's std lib.

These mods to the test prove it. (See attached patch.)

[Jim Bell <jim@…>]

Here's what it generates...

Running 1 test case...
unknown location(0): fatal error in "test_search_n": C:\Program Files\VS8\VC\INCLUDE\list(213) : Assertion failed: list iterator not dereferencable

..\libs\range\test\algorithm_test\search_n.cpp(34): last checkpoint: Pre-std: value: 9; n:2

*** 1 failure detected in test suite "Master Test Suite"

[Jim Bell <jim@…>]

A more complete patch & results...

Running 1 test case...
unknown location(0): fatal error in "test_search_n": C:\Program Files\VS8\VC\INCLUDE\list(213) : Assertion failed: list iterator not dereferencable

..\libs\range\test\algorithm_test\search_n.cpp(34): last checkpoint: Pre-std: class std::list<int,class std::allocator<int> >; value: 9; n:2; size:9

*** 1 failure detected in test suite "Master Test Suite"

[Jim Bell <jim@…>]

Also, can this mode of failure for relevant platforms be marked as an "expected" failure, allowing the entire range library to not be marked as fail/yellow on the main matrix?

[Neil Groves]

I'm going to tackle this slightly differently. There isn't an "expected" failure of Boost.Range this is unfortunately an expected failure of the Visual C++ standard library as you have described. Hence it is misleading to make my Boost.Range test fail since the algorithm actually works. This test result should pass. I shall modify the test to check for the correct result rather than test for equivalence to the standard library implementation.

[Jim Bell <jim@…>]

Excellent. A passing test is much more valuable than an explained failure.

I think it's very useful/helpful (and interesting) to see the standard library failure as my patch shows, and would love it to be kept around for the record, but if you can't find a place for it, I understand.

[Neil Groves]

I have altered the implementation as proposed earlier. It no longer uses the standard library implementation in either the core implementation or in the test. I shall monitor the progress on the trunk regression tests before a subsequent merge to the release branch.