[libcxx-commits] [PATCH] D68837: [libc++][P0202] Marked algorithms copy/copy_n/copy_if/copy_backward constexpr.

[Zoe Carver via Phabricator via libcxx-commits]

zoecarver added a comment.

`__libcpp_is_constant_evaluated` returns `false` in C++03 mode but, it still won't work as a template argument. Putting `#if`s around it will probably work, though.



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Comment at: libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp:22
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool test_constexpr()
+{
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It seems like these were already here. I think it would be really great if we could instead have a single test. For all these algorithms, what I would ideally like is just to change the return type to `bool`, add `constexpr`, and `return true` at the end. Then we can `static_assert` that `test` succeeds. If `assert` fails in the test, the `static_assert` will also fail. 

Maybe we can even develop a macro to wrap these functions and run them in both constexpr mode and normally. 


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  https://reviews.llvm.org/D68837/new/

https://reviews.llvm.org/D68837