Avoid std::atomic_init deprecated by P0883.

[BillyONeal]

Resolves #139

I don't think I've been successful in actually getting this to build; I apologize if there are typos here:

[lewissbaker]

I don't think I've been successful in actually getting this to build;

The build system is currently only looking for VS2017 compilers.
You will need to pull in the vs2019 branch to get the build system to find the VS2019 compiler (See PR #125).

[lewissbaker]

Thanks for the PR!

If you can fix up the multi_producer_sequencer constructor it should be good to merge.

[lewissbaker]

This loop still needs to run to initialise the elements of the array.
Each element is initialised to a different value (notice that seq is incremented inside the while condition).

Maybe something like this:

 SEQUENCE seq = initialSequence - (bufferSize - 1);
 do
 {
+#if __cpp_lib_atomic_value_initialization
+    m_published[seq & m_sequenceMask].store(seq, std::memory_order_relaxed);
+#else
     std::atomic_init(&m_published[seq & m_sequenceMask], seq);
+#endif
 } while (seq++ != initialSequence);

[BillyONeal]

Fixed up, thank you!

[BillyONeal]

The build system is currently only looking for VS2017 compilers.

Right, I put the VS2017 compiler on the PATH. (That's the -vcvars_ver=14.16.x in the dev prompt command) But I guess it might be looking in the 2017 installation directory or something like that.

This loop still needs to run to initialise the elements of the array.

Derp, stand by.

[lewissbaker]

But I guess it might be looking in the 2017 installation directory or something like that.

It uses vswhere to find the install-location of msvc.
I try to avoid relying on environment variables to help make the build a bit more repeatable.

You can modify the config.cake file to set the vcInstallDir variable explicitly as a last resort (it's just a Python script). I should probably add a command-line flag to allow setting this, as it does for clang.

[BillyONeal]

FYI, this ran against our compiler nightly builds last night and passed.