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| author | Jonathan Wakely <jwakely@redhat.com> | 2021-11-01 11:06:51 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2021-11-01 13:26:29 +0000 |
| commit | 91bac9fed5d082f0b180834110ebc0f46f97599a (patch) | |
| tree | fee69d3a9ffe1e3a6252ea0e4e09132e8b068883 /libstdc++-v3/include/std/valarray | |
| parent | bc5baac5c37d8da1931043c4bbeffa3ab93a8e91 (diff) | |
| download | gcc-91bac9fed5d082f0b180834110ebc0f46f97599a.zip gcc-91bac9fed5d082f0b180834110ebc0f46f97599a.tar.gz gcc-91bac9fed5d082f0b180834110ebc0f46f97599a.tar.bz2 | |
libstdc++: Fix range access for empty std::valarray [PR103022]
The std::begin and std::end overloads for std::valarray are defined in
terms of std::addressof(v[0]) which is undefined for an empty valarray.
libstdc++-v3/ChangeLog:
PR libstdc++/103022
* include/std/valarray (begin, end): Do not dereference an empty
valarray. Add noexcept and [[nodiscard]].
* testsuite/26_numerics/valarray/range_access.cc: Check empty
valarray. Check iterator properties. Run as well as compiling.
* testsuite/26_numerics/valarray/range_access2.cc: Likewise.
* testsuite/26_numerics/valarray/103022.cc: New test.
Diffstat (limited to 'libstdc++-v3/include/std/valarray')
| -rw-r--r-- | libstdc++-v3/include/std/valarray | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/libstdc++-v3/include/std/valarray b/libstdc++-v3/include/std/valarray index 5adc942..c6242eb 100644 --- a/libstdc++-v3/include/std/valarray +++ b/libstdc++-v3/include/std/valarray @@ -1210,9 +1210,10 @@ _DEFINE_BINARY_OPERATOR(>=, __greater_equal) * @param __va valarray. */ template<class _Tp> + [[__nodiscard__]] inline _Tp* - begin(valarray<_Tp>& __va) - { return std::__addressof(__va[0]); } + begin(valarray<_Tp>& __va) noexcept + { return __va.size() ? std::__addressof(__va[0]) : nullptr; } /** * @brief Return an iterator pointing to the first element of @@ -1220,9 +1221,10 @@ _DEFINE_BINARY_OPERATOR(>=, __greater_equal) * @param __va valarray. */ template<class _Tp> + [[__nodiscard__]] inline const _Tp* - begin(const valarray<_Tp>& __va) - { return std::__addressof(__va[0]); } + begin(const valarray<_Tp>& __va) noexcept + { return __va.size() ? std::__addressof(__va[0]) : nullptr; } /** * @brief Return an iterator pointing to one past the last element of @@ -1230,9 +1232,15 @@ _DEFINE_BINARY_OPERATOR(>=, __greater_equal) * @param __va valarray. */ template<class _Tp> + [[__nodiscard__]] inline _Tp* - end(valarray<_Tp>& __va) - { return std::__addressof(__va[0]) + __va.size(); } + end(valarray<_Tp>& __va) noexcept + { + if (auto __n = __va.size()) + return std::__addressof(__va[0]) + __n; + else + return nullptr; + } /** * @brief Return an iterator pointing to one past the last element of @@ -1240,9 +1248,15 @@ _DEFINE_BINARY_OPERATOR(>=, __greater_equal) * @param __va valarray. */ template<class _Tp> + [[__nodiscard__]] inline const _Tp* - end(const valarray<_Tp>& __va) - { return std::__addressof(__va[0]) + __va.size(); } + end(const valarray<_Tp>& __va) noexcept + { + if (auto __n = __va.size()) + return std::__addressof(__va[0]) + __n; + else + return nullptr; + } #endif // C++11 /// @} group numeric_arrays |