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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// std::views::transform
#include <ranges>
#include <cassert>
#include <concepts>
#include <type_traits>
#include <utility>
#include "test_macros.h"
#include "types.h"
template <class View, class T>
concept CanBePiped = requires (View&& view, T&& t) {
{ std::forward<View>(view) | std::forward<T>(t) };
};
struct NonCopyableFunction {
NonCopyableFunction(NonCopyableFunction const&) = delete;
template <class T>
constexpr T operator()(T x) const { return x; }
};
constexpr bool test() {
int buff[8] = {0, 1, 2, 3, 4, 5, 6, 7};
// Test `views::transform(f)(v)`
{
{
using Result = std::ranges::transform_view<MoveOnlyView, PlusOne>;
std::same_as<Result> auto result = std::views::transform(PlusOne{})(MoveOnlyView{buff});
assert(result.begin().base() == buff);
assert(result[0] == 1);
assert(result[1] == 2);
assert(result[2] == 3);
}
{
auto const partial = std::views::transform(PlusOne{});
using Result = std::ranges::transform_view<MoveOnlyView, PlusOne>;
std::same_as<Result> auto result = partial(MoveOnlyView{buff});
assert(result.begin().base() == buff);
assert(result[0] == 1);
assert(result[1] == 2);
assert(result[2] == 3);
}
}
// Test `v | views::transform(f)`
{
{
using Result = std::ranges::transform_view<MoveOnlyView, PlusOne>;
std::same_as<Result> auto result = MoveOnlyView{buff} | std::views::transform(PlusOne{});
assert(result.begin().base() == buff);
assert(result[0] == 1);
assert(result[1] == 2);
assert(result[2] == 3);
}
{
auto const partial = std::views::transform(PlusOne{});
using Result = std::ranges::transform_view<MoveOnlyView, PlusOne>;
std::same_as<Result> auto result = MoveOnlyView{buff} | partial;
assert(result.begin().base() == buff);
assert(result[0] == 1);
assert(result[1] == 2);
assert(result[2] == 3);
}
}
// Test `views::transform(v, f)`
{
using Result = std::ranges::transform_view<MoveOnlyView, PlusOne>;
std::same_as<Result> auto result = std::views::transform(MoveOnlyView{buff}, PlusOne{});
assert(result.begin().base() == buff);
assert(result[0] == 1);
assert(result[1] == 2);
assert(result[2] == 3);
}
// Test that one can call std::views::transform with arbitrary stuff, as long as we
// don't try to actually complete the call by passing it a range.
//
// That makes no sense and we can't do anything with the result, but it's valid.
{
struct X { };
auto partial = std::views::transform(X{});
(void)partial;
}
// Test `adaptor | views::transform(f)`
{
{
using Result = std::ranges::transform_view<std::ranges::transform_view<MoveOnlyView, PlusOne>, TimesTwo>;
std::same_as<Result> auto result = MoveOnlyView{buff} | std::views::transform(PlusOne{}) | std::views::transform(TimesTwo{});
assert(result.begin().base().base() == buff);
assert(result[0] == 2);
assert(result[1] == 4);
assert(result[2] == 6);
}
{
auto const partial = std::views::transform(PlusOne{}) | std::views::transform(TimesTwo{});
using Result = std::ranges::transform_view<std::ranges::transform_view<MoveOnlyView, PlusOne>, TimesTwo>;
std::same_as<Result> auto result = MoveOnlyView{buff} | partial;
assert(result.begin().base().base() == buff);
assert(result[0] == 2);
assert(result[1] == 4);
assert(result[2] == 6);
}
}
// Test SFINAE friendliness
{
struct NotAView { };
struct NotInvocable { };
static_assert(!CanBePiped<MoveOnlyView, decltype(std::views::transform)>);
static_assert( CanBePiped<MoveOnlyView, decltype(std::views::transform(PlusOne{}))>);
static_assert(!CanBePiped<NotAView, decltype(std::views::transform(PlusOne{}))>);
static_assert(!CanBePiped<MoveOnlyView, decltype(std::views::transform(NotInvocable{}))>);
static_assert(!std::is_invocable_v<decltype(std::views::transform)>);
static_assert(!std::is_invocable_v<decltype(std::views::transform), PlusOne, MoveOnlyView>);
static_assert( std::is_invocable_v<decltype(std::views::transform), MoveOnlyView, PlusOne>);
static_assert(!std::is_invocable_v<decltype(std::views::transform), MoveOnlyView, PlusOne, PlusOne>);
static_assert(!std::is_invocable_v<decltype(std::views::transform), NonCopyableFunction>);
}
{
static_assert(std::is_same_v<decltype(std::ranges::views::transform), decltype(std::views::transform)>);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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