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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::lazy_split
#include <ranges>
#include <array>
#include <cassert>
#include <concepts>
#include <string_view>
#include <utility>
#include "test_iterators.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 SomeView : std::ranges::view_base {
const std::string_view* v_;
constexpr SomeView(const std::string_view& v) : v_(&v) {}
constexpr auto begin() const { return v_->begin(); }
constexpr auto end() const { return v_->end(); }
};
struct NotAView { };
static_assert(!std::is_invocable_v<decltype(std::views::lazy_split)>);
static_assert(!std::is_invocable_v<decltype(std::views::lazy_split), SomeView, NotAView>);
static_assert(!std::is_invocable_v<decltype(std::views::lazy_split), NotAView, SomeView>);
static_assert( std::is_invocable_v<decltype(std::views::lazy_split), SomeView, SomeView>);
static_assert( CanBePiped<SomeView&, decltype(std::views::lazy_split)>);
static_assert( CanBePiped<char(&)[10], decltype(std::views::lazy_split)>);
static_assert(!CanBePiped<char(&&)[10], decltype(std::views::lazy_split)>);
static_assert(!CanBePiped<NotAView, decltype(std::views::lazy_split)>);
static_assert(std::same_as<decltype(std::views::lazy_split), decltype(std::ranges::views::lazy_split)>);
constexpr bool test() {
std::string_view input = "abc";
std::string_view sep = "a";
// Test that `std::views::lazy_split` is a range adaptor.
// Test `views::lazy_split(input, sep)`.
{
SomeView view(input);
using Result = std::ranges::lazy_split_view<SomeView, std::string_view>;
std::same_as<Result> decltype(auto) result = std::views::lazy_split(view, sep);
assert(result.base().begin() == input.begin());
assert(result.base().end() == input.end());
}
// Test `views::lazy_split(sep)(input)`.
{
SomeView view(input);
using Result = std::ranges::lazy_split_view<SomeView, std::string_view>;
std::same_as<Result> decltype(auto) result = std::views::lazy_split(sep)(view);
assert(result.base().begin() == input.begin());
assert(result.base().end() == input.end());
}
// Test `view | views::lazy_split`.
{
SomeView view(input);
using Result = std::ranges::lazy_split_view<SomeView, std::string_view>;
std::same_as<Result> decltype(auto) result = view | std::views::lazy_split(sep);
assert(result.base().begin() == input.begin());
assert(result.base().end() == input.end());
}
// Test `adaptor | views::lazy_split`.
{
SomeView view(input);
auto f = [](char c) { return c; };
auto partial = std::views::transform(f) | std::views::lazy_split(sep);
using Result = std::ranges::lazy_split_view<std::ranges::transform_view<SomeView, decltype(f)>, std::string_view>;
std::same_as<Result> decltype(auto) result = partial(view);
assert(result.base().base().begin() == input.begin());
assert(result.base().base().end() == input.end());
}
// Test `views::lazy_split | adaptor`.
{
SomeView view(input);
auto f = [](auto v) { return v; };
auto partial = std::views::lazy_split(sep) | std::views::transform(f);
using Result = std::ranges::transform_view<std::ranges::lazy_split_view<SomeView, std::string_view>, decltype(f)>;
std::same_as<Result> decltype(auto) result = partial(view);
assert(result.base().base().begin() == input.begin());
assert(result.base().base().end() == input.end());
}
// Test that one can call `std::views::lazy_split` 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 { };
[[maybe_unused]] auto partial = std::views::lazy_split(X{});
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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