Mark LWG3274 as complete. The feature test macro `__cpp_lib_span` was added in
`
6d2599e4f776d0cd88438cb82a00c4fc25cc3f67`.
https://wg21.link/p1024 mentions marking `span:::empty()` with
`[[nodiscard]]` which is not done yet. So, do that and add tests.
Reviewed By: ldionne, Quuxplusone, Mordante, #libc
Differential Revision: https://reviews.llvm.org/D111516
"`3272 <https://wg21.link/LWG3272>`__","``%I%p``\ should parse/format ``duration``\ since midnight","Belfast","",""
"`3259 <https://wg21.link/LWG3259>`__","The definition of *constexpr iterators* should be adjusted","Belfast","",""
"`3103 <https://wg21.link/LWG3103>`__","Errors in taking subview of ``span``\ should be ill-formed where possible","Belfast","",""
-"`3274 <https://wg21.link/LWG3274>`__","Missing feature test macro for ``<span>``\ ","Belfast","",""
+"`3274 <https://wg21.link/LWG3274>`__","Missing feature test macro for ``<span>``\ ","Belfast","|Complete|","11.0"
"`3276 <https://wg21.link/LWG3276>`__","Class ``split_view::outer_iterator::value_type``\ should inherit from ``view_interface``\ ","Belfast","",""
"`3277 <https://wg21.link/LWG3277>`__","Pre-increment on prvalues is not a requirement of ``weakly_incrementable``\ ","Belfast","",""
"`3149 <https://wg21.link/LWG3149>`__","``DefaultConstructible``\ should require default initialization","Belfast","|Complete|","13.0"
// [span.obs], span observers
constexpr size_type size() const noexcept;
constexpr size_type size_bytes() const noexcept;
- constexpr bool empty() const noexcept;
+ [[nodiscard]] constexpr bool empty() const noexcept;
// [span.elem], span element access
constexpr reference operator[](size_type idx) const;
return {data() + __offset, __count};
}
- _LIBCPP_INLINE_VISIBILITY constexpr size_type size() const noexcept { return _Extent; }
- _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes() const noexcept { return _Extent * sizeof(element_type); }
- _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return _Extent == 0; }
+ _LIBCPP_INLINE_VISIBILITY constexpr size_type size() const noexcept { return _Extent; }
+ _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes() const noexcept { return _Extent * sizeof(element_type); }
+ [[nodiscard]] _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return _Extent == 0; }
_LIBCPP_INLINE_VISIBILITY constexpr reference operator[](size_type __idx) const noexcept
{
return {data() + __offset, __count};
}
- _LIBCPP_INLINE_VISIBILITY constexpr size_type size() const noexcept { return __size; }
- _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes() const noexcept { return __size * sizeof(element_type); }
- _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return __size == 0; }
+ _LIBCPP_INLINE_VISIBILITY constexpr size_type size() const noexcept { return __size; }
+ _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes() const noexcept { return __size * sizeof(element_type); }
+ [[nodiscard]] _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return __size == 0; }
_LIBCPP_INLINE_VISIBILITY constexpr reference operator[](size_type __idx) const noexcept
{
--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// <span>
+
+// [[nodiscard]] constexpr bool empty() const noexcept;
+
+#include <span>
+
+void test() {
+ std::span<int> s1;
+ s1.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+
+ int arr[] = {1, 2, 3};
+ std::span<int, 3> s2{arr};
+ s2.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
// <span>
-// constexpr bool empty() const noexcept;
+// [[nodiscard]] constexpr bool empty() const noexcept;
//