…bug (microsoft#1592)

* Stop exporting winrt::impl::get_marshaler to workaround MSVC modules bug

* Include base.h in marshal.cpp to verify that include-then-import still works

…45 toolset (microsoft#1601)

* Migrate GitHub CI off VS 2022 (v143) to v145/VS 2026

* Add C++20 module test to CI; dynamic v143/v145 toolset selection

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

* Massive speedup to file_equal and file_to_string

* Properly cast the result of tellg() and handle filesystem errors more gracefully.

…es to Visual Studio proejct properties page (microsoft#1586)

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ryan Shepherd <ryansh@microsoft.com>

…microsoft#1606)

* Initial plan

* Fix C4819 warning: replace non-ASCII em dash with ASCII hyphen in base_macros.h comment

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

The code failed to handle three cases.

1. A cancellation is in progress when a cancellable awaitable begins.
2. A cancellation is in progress when a cancellable awaitable ends.
3. A cancellation is in progress when a cancel() request is made.

The m_canceller member has one of these three values:

* nullptr, meaning that there is nothing to cancel.
  It has this value when the coroutine is not awaiting, or if it is
  awaiting something that cannot be cancelled.
* cancelling_ptr, meaning that another thread (not the coroutine thread)
  is in the middle of cancellation request.
* function pointer, representing the function to call to cancel the await.

In case 1, we should not overwrite the canceling_ptr with the
function pointer, because only the code doing the cancel()
can transition into/out of cancelling_ptr.

In case 2, we intended to spin until the m_canceller is no longer
cancelling_ptr, but we used m_canceller.exchange(nullptr) in a loop,
which means that if m_canceller was cancelling_ptr, we overwrite it
with nullptr. As a result, the "while" loop always exits after one iteration.
We need to spin on the m_canceller without modifying it if it is cancelling_ptr.

In case 3, cancel() function resets m_cancelling back to nullptr,
even if the value was cancelling_ptr on entry, prematurely declaring
that the existing cancel() has completed. If the original value was
cancelling_ptr, we should leave it that way.

There are still other cases not handled:

* Coroutine already cancelled when a co_await starts.

In this case, we never call the canceller, so the coroutine fails
to propagate cancellation. This will require a broader fix, so I'm not
going to fix it in this PR. This PR is primarily about fixing the crash
caused by case 2. Cases 1 and 3 were fixed opportunistically.

base_types.h uses std::ratio_multiply, which is defined in <ratio>. Under strict include-what-you-use rules not referencing this header can lead to weird build breaks.