Move [[nodiscard]] and [[maybe_unused]] in front of host/device declarations

[StewMH]

Make HIP happy

[stephenswat]

I like it, but can we somehow add a CI job so we don't keep reintroducing these mistakes?

[krasznaa]

Indeed, we'd need a recipe soon about how you do these builds. So that they could be more automated.

Though, since I expect that things are not working yet, I don't think it's necessarily for this PR to sort it out.

[krasznaa]

I'm not in love with the lack of a space in front of [[maybe_unused]]. 🤔

[StewMH]

I don't like it either but it is clang-format's preference. I think we would need to update the clang-format version used by pre-commit. If I update to v19.1.7, I get this:

/**
 * traccc library, part of the ACTS project (R&D line)
 *
 * (c) 2024 CERN for the benefit of the ACTS project
 *
 * Mozilla Public License Version 2.0
 */

#pragma once

// Project include(s).
#include "traccc/definitions/qualifiers.hpp"
#include "traccc/edm/silicon_cell_collection.hpp"

namespace traccc {
struct [[maybe_unused]] channel0_major_cell_order_relation {
    template <typename T1, typename T2>
    [[maybe_unused]] TRACCC_HOST_DEVICE bool operator()(
        const edm::silicon_cell<T1>& a, const edm::silicon_cell<T2>& b) const {
        if (a.module_index() == b.module_index()) {
            if (a.channel1() == b.channel1()) {
                return a.channel0() <= b.channel0();
            } else {
                return a.channel1() <= b.channel1();
            }
        } else {
            return true;
        }
    }
};
}  // namespace traccc

which looks nice to me, but there are lots of other changes to other files.

[StewMH]

This is all stuff around the margins of @CrossR's big upcoming PR to introduce track fitting to Alpaka - once that's ready it will be tested by the current CI.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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