This file uses std::exception, so it should include the appropriate header.
Normally it gets the STL's <exception> header included via the gsl/assert file, but this is skipped with _HAS_EXCEPTIONS=0. I understand _HAS_EXCEPTIONS is undocumented and unsupported, but regardless, the appropriate header should be included here.
Alternatively, gsl/narrow should be modified to support _HAS_EXCEPTIONS=0, like gsl/assert was. But I'm not proposing that change. <exception> does define std::exception even with _HAS_EXCEPTIONS=0.
In the implementation of gsl::narrow, there is a comparison `static_cast<U>(t) != u` which may be comparing two floats.
The comparison here is done purposefully to categorize ill effects of narrowing conversion, since the values being compared *should* be the same when compared with `operator==`.
Note, using #pragma GCC will suppress this warning for both GCC and Clang.
[SF.12: Prefer the quoted form of #include for files relative to the including file and the angle bracket form everywhere else](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Rs-incform)
Additionally changed #include order in `span` so that all `span_ext` is in the GSL include block and not in the STL include block.
Fixes issues #1025.
Co-authored-by: Werner Henze <w.henze@avm.de>
* move span specialization of 'at' to <gsl/span> and update the parameter to be taken by reference
* undid previous changes and acted upon decisions made in maintainer sync. Fixed tests failing in /kernel mode
* ran clang-format on the include folder
* ran clang-format on the test folder
Co-authored-by: Jordan Maples <jordan.maples@microsoft.com>
