Safety improvements

[codecov[bot]]

Codecov Report

Base: 97.03% // Head: 97.88% // Increases project coverage by +0.84% :tada:

Coverage data is based on head (e96655c) compared to base (d39aaac). Patch coverage: 97.46% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #25 +/- ## ========================================== + Coverage 97.03% 97.88% +0.84% ========================================== Files 52 55 +3 Lines 1484 1749 +265 ========================================== + Hits 1440 1712 +272 + Misses 44 37 -7 ``` | [Impacted Files](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle) | Coverage Δ | | |---|---|---| | [include/flux/op/split.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L29wL3NwbGl0LmhwcA==) | `90.00% <62.50%> (ø)` | | | [include/flux/core/numeric.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvbnVtZXJpYy5ocHA=) | `90.00% <90.00%> (ø)` | | | [include/flux/op/begin\_end.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L29wL2JlZ2luX2VuZC5ocHA=) | `90.90% <90.90%> (ø)` | | | [include/flux/op/chain.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L29wL2NoYWluLmhwcA==) | `97.11% <93.33%> (ø)` | | | [include/flux/source/range.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L3NvdXJjZS9yYW5nZS5ocHA=) | `98.30% <98.30%> (ø)` | | | [include/flux/core/assert.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvYXNzZXJ0LmhwcA==) | `100.00% <100.00%> (ø)` | | | [include/flux/core/default\_impls.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvZGVmYXVsdF9pbXBscy5ocHA=) | `100.00% <100.00%> (ø)` | | | [include/flux/core/inline\_sequence\_base.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvaW5saW5lX3NlcXVlbmNlX2Jhc2UuaHBw) | `92.30% <100.00%> (+2.30%)` | :arrow_up: | | [include/flux/core/optional.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvb3B0aW9uYWwuaHBw) | `100.00% <100.00%> (ø)` | | | [include/flux/core/sequence\_access.hpp](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle#diff-aW5jbHVkZS9mbHV4L2NvcmUvc2VxdWVuY2VfYWNjZXNzLmhwcA==) | `96.96% <100.00%> (+0.62%)` | :arrow_up: | | ... and [31 more](https://codecov.io/gh/tcbrindle/flux/pull/25?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle) | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Tristan+Brindle)

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