1 // { dg-do compile { target c++11 } } 2 3 // Copyright (C) 2015-2021 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 // 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 // 16 // You should have received a copy of the GNU General Public License along 17 // with this library; see the file COPYING3. If not see 18 // <http://www.gnu.org/licenses/>. 19 20 #include <type_traits> 21 22 template<typename T, typename I0, typename... I> 23 struct smallest_rank 24 : std::conditional< sizeof(T) == sizeof(I0), 25 I0, 26 typename smallest_rank<T, I...>::type > 27 { }; 28 29 template<typename T, typename I0> 30 struct smallest_rank<T, I0> 31 { using type = I0; }; 32 33 template<typename T> 34 using smallest_rank_t 35 = typename smallest_rank<typename std::remove_cv<T>::type, 36 signed char, signed short, signed int, 37 signed long, signed long long>::type; 38 39 using std::make_signed; 40 using std::is_same; 41 42 enum E1 : char { }; 43 using I1 = smallest_rank_t<E1>; 44 static_assert(is_same<make_signed<E1>::type, I1>::value, ""); 45 static_assert(is_same<make_signed<E1 const>::type, I1 const>::value, ""); 46 47 enum E2 : short { }; 48 using I2 = smallest_rank_t<E2>; 49 static_assert(is_same<make_signed<E2>::type, I2>::value, ""); 50 static_assert(is_same<make_signed<E2 const>::type, I2 const>::value, ""); 51 52 enum E3 : int { }; 53 using I3 = smallest_rank_t<E3>; 54 static_assert(is_same<make_signed<E3>::type, I3>::value, ""); 55 static_assert(is_same<make_signed<E3 const>::type, I3 const>::value, ""); 56 57 enum E4 : long { }; 58 using I4 = smallest_rank_t<E4>; 59 static_assert(is_same<make_signed<E4>::type, I4>::value, ""); 60 static_assert(is_same<make_signed<E4 const>::type, I4 const>::value, ""); 61 62 // PR libstdc++/60333 63 enum E5 : long long { }; 64 using I5 = smallest_rank_t<E5>; 65 static_assert(is_same<make_signed<E5>::type, I5>::value, ""); 66 static_assert(is_same<make_signed<E5 const>::type, I5 const>::value, ""); 67 68 // PR libstdc++/85951 69 using I6 = smallest_rank_t<char16_t>; 70 static_assert(is_same<make_signed<char16_t>::type, I6>::value, ""); 71 static_assert(is_same<make_signed<char16_t const>::type, I6 const>::value, ""); 72 using I7 = smallest_rank_t<char32_t>; 73 static_assert(is_same<make_signed<char32_t>::type, I7>::value, ""); 74 static_assert(is_same<make_signed<char32_t const>::type, I7 const>::value, ""); 75 #ifdef _GLIBCXX_USE_WCHAR_T 76 using I8 = smallest_rank_t<wchar_t>; 77 static_assert(is_same<make_signed<wchar_t>::type, I8>::value, ""); 78 static_assert(is_same<make_signed<wchar_t const>::type, I8 const>::value, ""); 79 #endif 80