| // Copyright (C) 2019-2021 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++2a" } |
| // { dg-do run { target c++2a } } |
| |
| #include <compare> |
| #include <limits> |
| #include <testsuite_hooks.h> |
| |
| using std::weak_order; |
| using std::weak_ordering; |
| |
| void |
| test01() |
| { |
| const int one = 1, two = 2; |
| |
| static_assert( weak_order(one, two) == weak_ordering::less ); |
| static_assert( weak_order(one, one) == weak_ordering::equivalent ); |
| static_assert( weak_order(two, one) == weak_ordering::greater ); |
| static_assert( noexcept(weak_order(1, 1)) ); |
| } |
| |
| constexpr weak_ordering different_cv_quals(int i, const int j) |
| { |
| return weak_order(i, j); |
| } |
| |
| void |
| test02() |
| { |
| const int fortytwo = 42, nines = 999, lots = 1000; |
| |
| static_assert( different_cv_quals(fortytwo, nines) == weak_ordering::less ); |
| static_assert( different_cv_quals(-nines, -nines) == weak_ordering::equivalent ); |
| static_assert( different_cv_quals(-nines, -lots) == weak_ordering::greater ); |
| } |
| |
| void |
| test03() |
| { |
| constexpr double zero = 0.0; |
| static_assert( weak_order(zero, zero) == weak_ordering::equivalent ); |
| static_assert( weak_order(-zero, -zero) == weak_ordering::equivalent ); |
| static_assert( weak_order(-zero, zero) == weak_ordering::equivalent ); |
| static_assert( weak_order(zero, -zero) == weak_ordering::equivalent ); |
| |
| constexpr double min = std::numeric_limits<double>::lowest(); |
| constexpr double max = std::numeric_limits<double>::max(); |
| constexpr double nan = std::numeric_limits<double>::quiet_NaN(); |
| constexpr double inf = std::numeric_limits<double>::infinity(); |
| constexpr double denorm = std::numeric_limits<double>::denorm_min(); |
| constexpr double smallest = std::numeric_limits<double>::min(); |
| constexpr double epsilon = std::numeric_limits<double>::epsilon(); |
| static_assert( weak_order(denorm, smallest) == weak_ordering::less ); |
| static_assert( weak_order(denorm, 0.0) == weak_ordering::greater ); |
| // FIXME: these should all use static_assert |
| VERIFY( weak_order(0.0, nan) == weak_ordering::less ); |
| static_assert( weak_order(nan, nan) == weak_ordering::equivalent ); |
| static_assert( weak_order(nan, -nan) == weak_ordering::greater ); |
| static_assert( weak_order(-nan, nan) == weak_ordering::less ); |
| VERIFY( weak_order(nan, 0.0) == weak_ordering::greater ); |
| VERIFY( weak_order(-nan, 0.0) == weak_ordering::less ); |
| VERIFY( weak_order(-nan, min) == weak_ordering::less ); |
| static_assert( weak_order(-inf, min) == weak_ordering::less ); |
| VERIFY( weak_order(-nan, -inf) == weak_ordering::less ); |
| VERIFY( weak_order(-inf, -nan) == weak_ordering::greater ); |
| static_assert( weak_order(max, inf) == weak_ordering::less ); |
| static_assert( weak_order(inf, max) == weak_ordering::greater ); |
| VERIFY( weak_order(inf, nan) == weak_ordering::less ); |
| static_assert( weak_order(1.0, 1.0+epsilon) == weak_ordering::less ); |
| } |
| |
| namespace N |
| { |
| struct X { int i; }; |
| |
| constexpr weak_ordering operator<=>(X l, X r) |
| { |
| if (l.i < 0 && r.i < 0) |
| return weak_ordering::equivalent; |
| return r.i <=> l.i; |
| } |
| |
| constexpr bool operator==(X l, X r) { return std::is_eq(l <=> r); } |
| |
| static_assert(std::three_way_comparable<X>); |
| } |
| |
| void |
| test04() |
| { |
| using N::X; |
| X one{1}; |
| X negone{-1}; |
| |
| // FIXME: these should all use static_assert |
| VERIFY( weak_order(one, X{1}) == weak_ordering::equivalent ); |
| VERIFY( weak_order(negone, X{-2}) == weak_ordering::equivalent ); |
| VERIFY( weak_order(one, X{2}) == weak_ordering::greater ); |
| static_assert( !noexcept(weak_order(X{1}, X{2})) ); |
| } |
| |
| int main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| test04(); |
| } |