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| author | Patrick Palka <ppalka@redhat.com> | 2024-01-16 21:20:12 -0500 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2024-01-16 21:20:12 -0500 |
| commit | 98966f32f906303cd7d2e1c418f320c483e6dcbe (patch) | |
| tree | 809104721709d915e6696caa9a46a622534a4dd9 | |
| parent | 1a17797496f72982c1c802725704a9aaf01218b5 (diff) | |
| download | gcc-98966f32f906303cd7d2e1c418f320c483e6dcbe.zip gcc-98966f32f906303cd7d2e1c418f320c483e6dcbe.tar.gz gcc-98966f32f906303cd7d2e1c418f320c483e6dcbe.tar.bz2 | |
libstdc++: Implement P2540R1 change to views::cartesian_product()
This paper changes the identity element of views::cartesian_product to a
singleton range instead of an empty range. It was approved alongside
the main cartesian_product paper P2374R4, but unfortunately was overlooked
when implementing the main paper.
libstdc++-v3/ChangeLog:
* include/std/ranges (views::_CartesianProduct::operator()):
Adjust identity case as per P2540R1.
* testsuite/std/ranges/cartesian_product/1.cc (test01):
Adjust expected result of the identity case.
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
| -rw-r--r-- | libstdc++-v3/include/std/ranges | 2 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc | 6 |
2 files changed, 4 insertions, 4 deletions
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 3135e6f..7ef835f 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -8748,7 +8748,7 @@ namespace views::__adaptor operator() [[nodiscard]] (_Ts&&... __ts) const { if constexpr (sizeof...(_Ts) == 0) - return views::empty<tuple<>>; + return views::single(tuple{}); else return cartesian_product_view<all_t<_Ts>...>(std::forward<_Ts>(__ts)...); } diff --git a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc index f69f965..7281cd8 100644 --- a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc +++ b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc @@ -24,9 +24,9 @@ test01() int w[] = {9}; auto v0 = views::cartesian_product(); - VERIFY( ranges::end(v0) - ranges::begin(v0) == 0 ); - VERIFY( ranges::size(v0) == 0 ); - VERIFY( ranges::empty(v0) ); + VERIFY( ranges::end(v0) - ranges::begin(v0) == 1 ); + VERIFY( ranges::size(v0) == 1 ); + VERIFY( !ranges::empty(v0) ); auto v1 = views::cartesian_product(x); VERIFY( ranges::end(v1) - ranges::begin(v1) == 3 ); |