| // Copyright (C) 2020-2021 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 <algorithm> |
| #include <ranges> |
| #include <testsuite_hooks.h> |
| #include <testsuite_iterators.h> |
| |
| using __gnu_test::test_range; |
| 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}; |
| auto is_odd = [] (int i) { return i%2==1; }; |
| auto v = x | views::transform(is_odd); |
| VERIFY( ranges::equal(v, (int[]){1,0,1,0,1}) ); |
| using R = decltype(v); |
| static_assert(std::same_as<bool, decltype(*ranges::begin(v))>); |
| static_assert(ranges::view<R>); |
| static_assert(ranges::sized_range<R>); |
| static_assert(ranges::random_access_range<R>); |
| } |
| |
| struct X |
| { |
| int i,j; |
| }; |
| |
| void |
| test02() |
| { |
| X x[] = {{1,2},{3,4},{5,6},{7,8},{9,10}}; |
| test_range<X, random_access_iterator_wrapper> rx(x); |
| auto v = rx | views::transform(&X::i); |
| VERIFY( ranges::size(v) == 5 ); |
| VERIFY( ranges::distance(v.begin(), v.end()) == 5 ); |
| VERIFY( ranges::equal(v, (int[]){1,3,5,7,9}) ); |
| VERIFY( ranges::equal(v | views::reverse, (int[]){9,7,5,3,1}) ); |
| using R = decltype(v); |
| static_assert(std::same_as<int&, decltype(*ranges::begin(v))>); |
| static_assert(std::same_as<int, std::iter_value_t<ranges::iterator_t<R>>>); |
| static_assert(ranges::view<R>); |
| static_assert(ranges::sized_range<R>); |
| static_assert(!ranges::common_range<R>); |
| static_assert(ranges::random_access_range<R>); |
| } |
| |
| void |
| test03() |
| { |
| auto id = [] (int i) { return i; }; |
| auto v = views::iota(0) | (views::filter(id) |
| | views::transform(id) |
| | views::take(5)); |
| VERIFY( ranges::equal(v, (int[]){1,2,3,4,5}) ); |
| } |
| |
| void |
| test04() |
| { |
| // LWG 3301 |
| { |
| auto f = [] (int x) { return x; }; |
| int x[] = {1,2,3,4,5}; |
| auto v = x | views::transform(f); |
| auto i = v.begin(); |
| using Cat = decltype(i)::iterator_category; |
| static_assert(std::same_as<Cat, std::input_iterator_tag>); |
| } |
| |
| { |
| auto f = [] (int &x) -> int& { return x; }; |
| int x[] = {1,2,3,4,5}; |
| auto v = x | views::transform(f); |
| auto i = v.begin(); |
| using Cat = decltype(i)::iterator_category; |
| static_assert(std::derived_from<Cat, std::forward_iterator_tag>); |
| } |
| } |
| |
| void |
| test05() |
| { |
| int x[] = {1,2,3,4,5}; |
| auto i = std::counted_iterator(x, 5); |
| auto r = ranges::subrange{i, std::default_sentinel}; |
| auto v = r | views::transform(std::negate{}); |
| |
| // Verify that _Iterator<false> is implicitly convertible to _Iterator<true>. |
| static_assert(!std::same_as<decltype(ranges::begin(v)), |
| decltype(ranges::cbegin(v))>); |
| auto a = ranges::cbegin(v); |
| a = ranges::begin(v); |
| |
| // Verify that _Sentinel<false> is implicitly convertible to _Sentinel<true>. |
| static_assert(!ranges::common_range<decltype(v)>); |
| static_assert(!std::same_as<decltype(ranges::end(v)), |
| decltype(ranges::cend(v))>); |
| auto b = ranges::cend(v); |
| b = ranges::end(v); |
| } |
| |
| struct Y |
| { |
| using Iter = __gnu_test::forward_iterator_wrapper<Y>; |
| |
| friend auto operator-(Iter l, Iter r) { return l.ptr - r.ptr; } |
| }; |
| |
| void |
| test06() |
| { |
| using ranges::next; |
| using ranges::begin; |
| |
| // LWG 3483 |
| Y y[3]; |
| __gnu_test::test_forward_range<Y> r(y); |
| auto v = views::transform(r, std::identity{}); |
| auto b = begin(v); |
| static_assert( !ranges::random_access_range<decltype(r)> ); |
| static_assert( std::sized_sentinel_for<decltype(b), decltype(b)> ); |
| VERIFY( (next(b, 1) - b) == 1 ); |
| const auto v_const = v; |
| auto b_const = begin(v_const); |
| VERIFY( (next(b_const, 2) - b_const) == 2 ); |
| } |
| |
| void |
| test07() |
| { |
| int x[] = {1,2,3,4,5}; |
| auto v1 = views::transform([] (auto& x) { return &x; }); |
| auto v2 = views::transform([] (auto x) { return *x; }); |
| auto v = x | (v1 | v2); |
| VERIFY( ranges::equal(v, x) ); |
| } |
| |
| template<auto transform = views::transform> |
| void |
| test08() |
| { |
| // Verify SFINAE behavior. |
| extern int x[5]; |
| auto f = [] (int* e) { return e; }; |
| static_assert(!requires { transform(); }); |
| static_assert(!requires { transform(x, f, f); }); |
| static_assert(!requires { transform(x, f); }); |
| static_assert(!requires { transform(f)(x); }); |
| static_assert(!requires { x | (transform(f) | views::all); }); |
| static_assert(!requires { (transform(f) | views::all)(x); }); |
| static_assert(!requires { transform | views::all; }); |
| static_assert(!requires { views::all | transform; }); |
| } |
| |
| int |
| main() |
| { |
| test01(); |
| test02(); |
| test03(); |
| test04(); |
| test05(); |
| test06(); |
| test07(); |
| test08(); |
| } |