Without this change, the guideline
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c89-make-a-hash-noexcept
would be violated.
The test fails before the changes here:
```
tests/pointers_tests.cpp:102:23: error: static assertion failed due to requirement 'noexcept(std::hash<gsl::not_null<std::shared_ptr<int>>>{}(std::declval()))': gsl::not_null hash operator must be noexcept
102 | static_assert(noexcept(std::hash<Key>{}(std::declval<Key>())),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tests/pointers_tests.cpp:108:23: error: static assertion failed due to requirement 'noexcept(std::hash<gsl::strict_not_null<std::shared_ptr<int>>>{}(std::declval()))': gsl::strict_not_null hash operator must be noexcept
108 | static_assert(noexcept(std::hash<Key>{}(std::declval<Key>())),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Co-authored-by: MarcoFalke <*~=`'#}+{/-|&$^_@721217.xyz>
- `strict_not_null<std::unique_ptr<int>>{ std::make_unique<int>()}` failed to compile
- `strict_not_null` ctor needs to move the passed `unique_ptr`, not copy
- Copied `not_null` `TestNotNullConstructors` for `strict_not_null`
- The `noexcept` specifiers on the `strict_not_null` and `not_null` constructors were out of sync.
- Added unit test for `not_null<unique_ptr<T>>` and for `strict_not_null<unique_ptr<T>>`
- Added unit test for `gsl::swap` for two `strict_not_null`
- Added unit test for `gsl::swap` for `not_null` and `strict_not_null`
Co-authored-by: Werner Henze <w.henze@avm.de>
maflcko
Carson Radtke
Werner Henze