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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-11-01 13:47:24 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-11-02 12:54:16 +0000 |
| commit | f4874691812bc20e3d8e3302db439c27f30c472c (patch) | |
| tree | 99b9be831ea469f73b4e8ea163fde347b07a2f70 | |
| parent | cf35818a390e7cb4b1a4fa70c243ede59d6cbbac (diff) | |
| download | gcc-f4874691812bc20e3d8e3302db439c27f30c472c.zip gcc-f4874691812bc20e3d8e3302db439c27f30c472c.tar.gz gcc-f4874691812bc20e3d8e3302db439c27f30c472c.tar.bz2 | |
libstdc++: Remove unnecessary variant member in std::expected
Hui Xie pointed out that we don't need a dummy member in the union,
because all constructors always initialize either _M_val or _M_unex.
We still need the _M_void member of the expected<void, E>
specialization, because the constructor has to initialize something when
not using the _M_unex member.
libstdc++-v3/ChangeLog:
* include/std/expected (expected::_M_invalid): Remove.
| -rw-r--r-- | libstdc++-v3/include/std/expected | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/libstdc++-v3/include/std/expected b/libstdc++-v3/include/std/expected index 3ee13aa..e491ce4 100644 --- a/libstdc++-v3/include/std/expected +++ b/libstdc++-v3/include/std/expected @@ -359,7 +359,7 @@ namespace __expected requires is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Er> && (!is_trivially_copy_constructible_v<_Tp> || !is_trivially_copy_constructible_v<_Er>) - : _M_invalid(), _M_has_value(__x._M_has_value) + : _M_has_value(__x._M_has_value) { if (_M_has_value) std::construct_at(__builtin_addressof(_M_val), __x._M_val); @@ -376,7 +376,7 @@ namespace __expected requires is_move_constructible_v<_Tp> && is_move_constructible_v<_Er> && (!is_trivially_move_constructible_v<_Tp> || !is_trivially_move_constructible_v<_Er>) - : _M_invalid(), _M_has_value(__x._M_has_value) + : _M_has_value(__x._M_has_value) { if (_M_has_value) std::construct_at(__builtin_addressof(_M_val), @@ -394,7 +394,7 @@ namespace __expected expected(const expected<_Up, _Gr>& __x) noexcept(__and_v<is_nothrow_constructible<_Tp, const _Up&>, is_nothrow_constructible<_Er, const _Gr&>>) - : _M_invalid(), _M_has_value(__x._M_has_value) + : _M_has_value(__x._M_has_value) { if (_M_has_value) std::construct_at(__builtin_addressof(_M_val), __x._M_val); @@ -410,7 +410,7 @@ namespace __expected expected(expected<_Up, _Gr>&& __x) noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>, is_nothrow_constructible<_Er, _Gr>>) - : _M_invalid(), _M_has_value(__x._M_has_value) + : _M_has_value(__x._M_has_value) { if (_M_has_value) std::construct_at(__builtin_addressof(_M_val), @@ -890,7 +890,6 @@ namespace __expected } union { - struct { } _M_invalid; _Tp _M_val; _Er _M_unex; }; |