Initial find script

[Ryanf55]

This is the PR for #13, currently in draft to garner feedback.

• Let's somehow test the RST docs are correct
• How are we expecting a user to install FindASIO.cmake
• TODO: Add this to CI
• TODO: Add cmake pre-commit hook to continue to lint the file

Note: This work was done on behalf of AeroVironment Inc.

[OlivierLDff]

Looks fine, waiting for CI & doc 🚀

[Ryanf55]

Unclear - do we need to add ASIO_FOUND to the REQUIRED_VARS?

[OlivierLDff]

Isn't it supposed to do it by itself? Only a test can make sure of that.

[Ryanf55]

Yea, it would be nicer if the CMake docs would explain this point. I'll do a test.

[Ryanf55]

Right now, the version is required. Since this works since asio 0.3.8, I'd just recommend making it always part of the interface.

[OlivierLDff]

What work since asio 0.3.8?

[Ryanf55]

Parsing the asio/version.hpp for version info using the same regex.
Since 0.3.8, the version format has been the same and the regex is the same.

[Ryanf55]

I would like to understand what to do with the asio macros:

https://think-async.com/Asio/asio-1.28.0/doc/asio/using.html#asio.using.macros

Should these all be exposed as CMake OPTIONs, then set here in target_compile_definitions and a call to target_compile_options?

[OlivierLDff]

Hard to answer here. It was easy when cmake when creating the asio target. I guess when asio is system installed this is the header only version no?

[Ryanf55]

On ubuntu, I get the asio.cpp file but not the asio_ssl.cpp.

$ find /usr | grep asio | grep -v boost | grep cpp
/usr/include/asio/impl/src.cpp

From what I understand, which is used for the pre-compiled header, however 99% of asio is implemented in header files anyways. The find script here ideally should be able to support using asio in either mode. I have only gotten the header-only version working, pre-compiled has errors.

[OlivierLDff]

I guess action with matrix is the way to test everything

[Ryanf55]

Found a bug - if any of the major, minor, or patch versions are 0, the find_package_handle_standard_args reports the variables as not found.

[OlivierLDff]

That is odd, because 0.0.1 shoudl be a valid version or 1.0.0

[Ryanf55]

ASIO_VERSION_PATCH

Correct, that is a valid version, however I don't think you are supposed to put ASIO_VERSION_PATCH in the required variables. The math call should never fail.

We can assume if ASIO_VERSION exists, the other related version variables should work.

[OlivierLDff]

Seems fair