https://github.com/llvmbot created
https://github.com/llvm/llvm-project/pull/100145
Backport c2e4386
Requested by: @ldionne
>From 8325799d41659bd1ff72ed3d628732f2a72a5dc8 Mon Sep 17 00:00:00 2001
From: Mark de Wever <ko...@xs4all.nl>
Date: Tue, 23 Jul 2024 18:03:28 +0200
Subject: [PATCH] [libc++][vector<bool>] Tests shrink_to_fit requirement.
(#98009)
`vector<bool>`'s shrink_to_fit implementation is using the
"swap-to-free-container-resources-trick" which only shrinks when the
input vector is empty. Since the request to shrink_to_fit is
non-binding, this is a valid implementation. It is not a high-quality
implementation. Since `vector<bool>` is not a very popular container the
implementation has not been changed and only a test to validate the
non-growing property has been added.
This was discovered while investigating #95161.
(cherry picked from commit c2e438675754b83c31d7d5ba40cb13fe77e795de)
---
.../vector.bool/shrink_to_fit.pass.cpp | 45 ++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git
a/libcxx/test/std/containers/sequences/vector.bool/shrink_to_fit.pass.cpp
b/libcxx/test/std/containers/sequences/vector.bool/shrink_to_fit.pass.cpp
index b39245cab7bf4..f8bcee31964bb 100644
--- a/libcxx/test/std/containers/sequences/vector.bool/shrink_to_fit.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector.bool/shrink_to_fit.pass.cpp
@@ -39,11 +39,54 @@ TEST_CONSTEXPR_CXX20 bool tests()
return true;
}
+#if TEST_STD_VER >= 23
+template <typename T>
+struct increasing_allocator {
+ using value_type = T;
+ std::size_t min_elements = 1000;
+ increasing_allocator() = default;
+
+ template <typename U>
+ constexpr increasing_allocator(const increasing_allocator<U>& other)
noexcept : min_elements(other.min_elements) {}
+
+ constexpr std::allocation_result<T*> allocate_at_least(std::size_t n) {
+ if (n < min_elements)
+ n = min_elements;
+ min_elements += 1000;
+ return std::allocator<T>{}.allocate_at_least(n);
+ }
+ constexpr T* allocate(std::size_t n) { return allocate_at_least(n).ptr; }
+ constexpr void deallocate(T* p, std::size_t n) noexcept {
std::allocator<T>{}.deallocate(p, n); }
+};
+
+template <typename T, typename U>
+bool operator==(increasing_allocator<T>, increasing_allocator<U>) {
+ return true;
+}
+
+// https://github.com/llvm/llvm-project/issues/95161
+constexpr bool test_increasing_allocator() {
+ std::vector<bool, increasing_allocator<bool>> v;
+ v.push_back(1);
+ std::size_t capacity = v.capacity();
+ v.shrink_to_fit();
+ assert(v.capacity() <= capacity);
+ assert(v.size() == 1);
+
+ return true;
+}
+#endif // TEST_STD_VER >= 23
+
int main(int, char**)
{
- tests();
+ tests();
#if TEST_STD_VER > 17
static_assert(tests());
#endif
+#if TEST_STD_VER >= 23
+ test_increasing_allocator();
+ static_assert(test_increasing_allocator());
+#endif // TEST_STD_VER >= 23
+
return 0;
}
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
