| // Copyright (C) 2020-2023 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 <algorithm> |
| #include <ranges> |
| #include <testsuite_hooks.h> |
| #include <testsuite_iterators.h> |
| |
| using __gnu_test::test_range; |
| using __gnu_test::bidirectional_iterator_wrapper; |
| using __gnu_test::forward_iterator_wrapper; |
| using __gnu_test::random_access_iterator_wrapper; |
| |
| namespace ranges = std::ranges; |
| namespace views = std::ranges::views; |
| |
| void |
| test01() |
| { |
| int x[] = {1,2,3,4,5,6}; |
| auto is_odd = [] (int i) { return i%2==1; }; |
| auto v = x | views::filter(is_odd); |
| using R = decltype(v); |
| static_assert(std::same_as<int&, decltype(*v.begin())>); |
| static_assert(ranges::view<R>); |
| static_assert(ranges::input_range<R>); |
| static_assert(ranges::common_range<R>); |
| static_assert(!ranges::sized_range<R>); |
| static_assert(ranges::bidirectional_range<R>); |
| static_assert(!ranges::random_access_range<R>); |
| static_assert(ranges::range<views::all_t<R>>); |
| VERIFY( ranges::equal(v, (int[]){1,3,5}) ); |
| VERIFY( ranges::equal(v | views::reverse, (int[]){5,3,1}) ); |
| VERIFY( v.pred()(3) == true ); |
| VERIFY( v.pred()(4) == false ); |
| } |
| |
| void |
| test02() |
| { |
| int x[] = {1,2,3,4,5,6}; |
| auto f = [flag=false] (int) mutable { return flag = !flag; }; |
| auto v = views::filter(f)(x); |
| using R = decltype(v); |
| static_assert(std::same_as<int&, decltype(*v.begin())>); |
| static_assert(ranges::range<R>); |
| static_assert(std::copyable<R>); |
| static_assert(!ranges::view<const R>); |
| VERIFY( ranges::equal(v, (int[]){1,3,5}) ); |
| } |
| |
| struct X |
| { |
| int i, j; |
| }; |
| |
| void |
| test03() |
| { |
| X x[] = {{1,3}, {2,5}, {3,7}, {4,9}}; |
| test_range<X, bidirectional_iterator_wrapper> rx(x); |
| auto v = rx | views::filter([] (auto&& p) { return p.i%2==0; }); |
| int sum = 0; |
| for (auto i = v.begin(); i != v.end(); ++i) |
| sum += i->j; |
| VERIFY( sum == 14 ); |
| } |
| |
| void |
| test04() |
| { |
| auto yes = [] (int) { return true; }; |
| VERIFY( ranges::equal(views::iota(0) | views::filter(yes) | views::take(1), |
| (int[]){0}) ); |
| } |
| |
| // The following tests that filter_view::begin caches its result. |
| |
| template<template<typename> typename wrapper> |
| struct test_view : ranges::view_base |
| { |
| bool begin_already_called = false; |
| static inline int x[] = {1,2,3,4,5}; |
| test_range<int, wrapper> rx{x}; |
| |
| auto |
| begin() |
| { |
| if (begin_already_called) |
| x[0] = 10; |
| begin_already_called = true; |
| return rx.begin(); |
| } |
| |
| auto |
| end() |
| { return rx.end(); } |
| }; |
| |
| template<template<typename> typename wrapper> |
| void |
| test05() |
| { |
| auto v = test_view<wrapper>{} | views::filter([] (int i) { return i%2 == 0; }); |
| VERIFY( ranges::equal(v, (int[]){2,4}) ); |
| VERIFY( ranges::equal(v, (int[]){2,4}) ); |
| } |
| |
| template<auto filter = views::filter> |
| void |
| test06() |
| { |
| // Verify SFINAE behavior. |
| extern int x[5]; |
| auto p = [] (int*) { return true; }; |
| static_assert(!requires { filter(); }); |
| static_assert(!requires { filter(x, p, p); }); |
| static_assert(!requires { filter(x, p); }); |
| static_assert(!requires { filter(p)(x); }); |
| static_assert(!requires { x | (filter(p) | views::all); }); |
| static_assert(!requires { (filter(p) | views::all)(x); }); |
| static_assert(!requires { filter | views::all; }); |
| static_assert(!requires { views::all | filter; }); |
| } |
| |
| constexpr bool |
| test07() |
| { |
| struct Pred |
| { |
| constexpr Pred() { } |
| constexpr Pred(const Pred&) { } |
| constexpr Pred(Pred&&) { } |
| // These make it non-copyable, so non-copyable-box<Pred> will provide |
| // assignment. |
| Pred& operator=(const Pred&) = delete; |
| Pred& operator=(Pred&&) = delete; |
| |
| bool operator()(int i) const { return i < 10; } |
| }; |
| |
| int i = 0; |
| ranges::filter_view v(views::single(i), Pred{}); |
| // LWG 3572. copyable-box should be fully constexpr |
| v = v; |
| v = std::move(v); |
| |
| return true; |
| } |
| |
| static_assert( test07() ); |
| |
| int |
| main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| test04(); |
| test05<forward_iterator_wrapper>(); |
| test05<random_access_iterator_wrapper>(); |
| test06(); |
| test07(); |
| } |