[libcxx-commits] [PATCH] D150493: [libc++] Add concepts that ensure a given iterator meets the syntactic requirements

[Louis Dionne via Phabricator via libcxx-commits]

ldionne accepted this revision.
ldionne added a comment.
This revision is now accepted and ready to land.

LGTM w/ comments



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Comment at: libcxx/include/__iterator/cpp17_iterator_concepts.h:48
+template <class _Tp>
+concept __cpp17_copy_assignable = __cpp17_move_assignable<_Tp> && requires(_Tp __lhs, _Tp __rhs) {
+  { __lhs = __rhs } -> same_as<_Tp&>;
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Per http://eel.is/c++draft/utility.arg.requirements#1.6, `a = b` must work if `b` is const. Needs a test too.


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Comment at: libcxx/include/__iterator/cpp17_iterator_concepts.h:55-56
+
+template <class _Iter>
+concept __cpp17_equality_comparable = requires(_Iter __lhs, _Iter __rhs) {
+  { __lhs == __rhs } -> __boolean_testable;
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I'd suggest we use `_Tp` instead of `_Iter` here, this isn't limited to iterators.


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Comment at: libcxx/include/__iterator/cpp17_iterator_concepts.h:69
+    __cpp17_copy_constructible<_Iter> && __cpp17_copy_assignable<_Iter> && __cpp17_destructible<_Iter> &&
+    (is_signed_v<__iter_diff_t<_Iter>> || is_void_v<__iter_diff_t<_Iter>>)&&requires(_Iter __iter) {
+      { *__iter };
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Repository:
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  https://reviews.llvm.org/D150493/new/

https://reviews.llvm.org/D150493