diff options
| -rw-r--r-- | libstdc++-v3/ChangeLog | 6 | ||||
| -rw-r--r-- | libstdc++-v3/include/std/variant | 2 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/20_util/variant/87619.cc | 53 |
3 files changed, 60 insertions, 1 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 57a35f0..9dc705c 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2018-10-17 Ville Voutilainen <ville.voutilainen@gmail.com> + + PR libstdc++/87619 + * include/std/variant (__select_index): Fix an off-by-one. + * testsuite/20_util/variant/87619.cc: New. + 2018-10-16 Jonathan Wakely <jwakely@redhat.com> * include/bits/random.h (random_device) [!_GLIBCXX_USE_DEV_RANDOM]: diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant index ff340cf..d4d596b 100644 --- a/libstdc++-v3/include/std/variant +++ b/libstdc++-v3/include/std/variant @@ -362,7 +362,7 @@ namespace __variant template <typename... _Types> using __select_index = - typename __select_int::_Select_int_base<sizeof...(_Types) + 1, + typename __select_int::_Select_int_base<sizeof...(_Types), unsigned char, unsigned short>::type::value_type; diff --git a/libstdc++-v3/testsuite/20_util/variant/87619.cc b/libstdc++-v3/testsuite/20_util/variant/87619.cc new file mode 100644 index 0000000..e6f48fe --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/variant/87619.cc @@ -0,0 +1,53 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++17" } +// { dg-do compile { target c++17 } } + +#include <variant> +#include <utility> +#include <limits> + +template<std::size_t I> +struct S { +}; + +template <std::size_t... Is> +void f_impl(std::index_sequence<Is...>) +{ + using V = std::variant<S<Is>...>; + // For a variant of 255 alternatives the valid indices are [0,254] + // and index 255 means valueless-by-exception, so fits in one byte. + if constexpr (std::variant_size_v<V> <= + std::numeric_limits<unsigned char>::max()) + static_assert(sizeof(V) == 2); + else + static_assert(sizeof(V) > 2); +} + +template <std::size_t I> +void f() +{ + f_impl(std::make_index_sequence<I>{}); +} + +int main() +{ + f<std::numeric_limits<unsigned char>::max() - 1>(); + f<std::numeric_limits<unsigned char>::max()>(); + f<std::numeric_limits<unsigned char>::max() + 1>(); +} |