bloomberg/bsl — pull request #24 by apaprocki (2012-11-17 20:25:46+00:00)
Title: Fix -Wunused warning.

Fixes:

```
../groups/bsl/bslalg/bslalg_typetraitpair.t.cpp: In function ‘int main(int, char**)’:
../groups/bsl/bslalg/bslalg_typetraitpair.t.cpp:122: warning: unused variable ‘mX’ [-Wunused-variable]
```

Adds `BSLS_ANNOTATION_UNUSED` to prevent warning.