[PATCH] D33997: Implement the non-execution policy versions of `reduce` and `transform_reduce` for C++17

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added inline comments.


================
Comment at: include/numeric:145
+{
+    return reduce(__first, __last, __init, _VSTD::plus<>());
+}
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Missing _VSTD::


================
Comment at: include/numeric:153
+{
+    return reduce(__first, __last, 
+       typename iterator_traits<_InputIterator>::value_type{}, _VSTD::plus<>());
----------------
Missing _VSTD::


================
Comment at: include/numeric:209
+{
+	return transform_reduce(__first1, __last1, __first2, __init, _VSTD::plus<>(), _VSTD::multiplies<>());
+}
----------------
Missing _VSTD::


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Comment at: test/std/numerics/numeric.ops/reduce/reduce_iter_iter.pass.cpp:26
+{
+    static_assert( std::is_same<typename std::iterator_traits<decltype(first)>::value_type,
+                                decltype(std::reduce(first, last))>::value, "" );
----------------
Maybe use _v trait?


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Comment at: test/std/numerics/numeric.ops/reduce/reduce_iter_iter.pass.cpp:27
+    static_assert( std::is_same<typename std::iterator_traits<decltype(first)>::value_type,
+                                decltype(std::reduce(first, last))>::value, "" );
+    assert(std::reduce(first, last) == x);
----------------
May as well drop the `, ""` since this test requires C++17 anyway.


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Comment at: test/std/numerics/numeric.ops/reduce/reduce_iter_iter.pass.cpp:37
+    unsigned sa = sizeof(ia) / sizeof(ia[0]);
+    test(Iter(ia), Iter(ia), 0);
+    test(Iter(ia), Iter(ia+1), 1);
----------------
wash wrote:
>  Just to confirm, this should be 0 because the "default" init value is `iterator_traits<_InputIterator>::value_type{}`, and `int{}` gives you a determinate result (as opposed to `int()` which would not), correct?
`int()` also gives a determinate result.


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Comment at: test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_init_bop_uop.pass.cpp:36
+    _NOEXCEPT_(noexcept(_VSTD::forward<_Tp>(__x)))
+    -> decltype        (_VSTD::forward<_Tp>(__x))
+        { return        _VSTD::forward<_Tp>(__x); }
----------------
Maybe use `decltype(auto)` here?


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Comment at: test/std/numerics/numeric.ops/transform.reduce/transform_reduce_iter_iter_iter_init_op_op.pass.cpp:41
+    unsigned sa = sizeof(ia) / sizeof(ia[0]);
+    assert(sa == sizeof(ua) / sizeof(ua[0]));       // just to be sure
+
----------------
You could static_assert this if you make sa const.


https://reviews.llvm.org/D33997