Implements: std::ranges::any_view proposed in any_view (P3411R1).
Status: Under development and not yet ready for production use.
#include <beman/any_view/any_view.hpp>
#include <ranges>
#include <vector>
namespace bav = beman::any_view;
using opt = bav::any_view_options;
template <class T>
using proxy_any_view = bav::any_view<T, opt::input, T>;
constexpr auto sum(proxy_any_view<proxy_any_view<int>> views) {
auto result = 0;
for (auto view : views) {
for (const auto value : view) {
result += value;
}
}
return result;
}
static_assert(10 == sum(std::vector{std::vector{1, 2}, std::vector{3, 4}}));
constexpr auto iota(int n) { return std::views::iota(1) | std::views::take(n); };
static_assert(35 == sum(iota(5) | std::views::transform(iota)));
static_assert(22 == sum(std::vector{iota(1), iota(3), iota(5)}));Full code can be found in tests/beman/any_view/constexpr.test.cpp.
std::ranges::any_view is a class template that provides a type-erased interface for std::ranges::view.
It may additionally model other concepts like std::ranges::contiguous_range, std::ranges::sized_range,
std::ranges::borrowed_range, and std::copyable depending on the instantiation.
Use beman.any_view directly from CMake
For CMake based projects, you can include it as a dependency using the FetchContent module:
include(FetchContent)
FetchContent_Declare(
beman.any_view
GIT_REPOSITORY https://github.com/bemanproject/any_view.git
GIT_TAG main
EXCLUDE_FROM_ALL)
FetchContent_MakeAvailable(beman.any_view)You will also need to add beman::any_view to the link libraries of any targets that include beman/any_view/*.hpp in
their source or header files:
target_link_libraries(yourlib PUBLIC beman::any_view)ENUM (default)
Synopsis:
#define BEMAN_ANY_VIEW_USE_ENUM() 1
#define BEMAN_ANY_VIEW_USE_TRAITS() 0
#define BEMAN_ANY_VIEW_USE_NAMED() 0
namespace beman::any_view {
enum class any_view_options {
input = 0b0000000,
forward = 0b0000001,
bidirectional = 0b0000011,
random_access = 0b0000111,
contiguous = 0b0001111,
sized = 0b0010000,
borrowed = 0b0100000,
#if BEMAN_ANY_VIEW_USE_COPYABLE()
copyable = 0b1000000,
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
move_only = 0b1000000,
#endif
};
constexpr auto operator|(any_view_options l, any_view_options r) noexcept -> any_view_options;
constexpr auto operator&(any_view_options l, any_view_options r) noexcept -> any_view_options;
constexpr auto operator^(any_view_options l, any_view_options r) noexcept -> any_view_options;
constexpr auto operator~(any_view_options o) noexcept -> any_view_options;
constexpr auto operator|=(any_view_options& l, any_view_options r) noexcept -> any_view_options&;
constexpr auto operator&=(any_view_options& l, any_view_options r) noexcept -> any_view_options&;
constexpr auto operator^=(any_view_options& l, any_view_options r) noexcept -> any_view_options&;
template <class ElementT,
any_view_options OptionsV = any_view_options::input,
class RefT = ElementT&,
class RValueRefT = /*as-rvalue-t*/<RefT>,
class DiffT = std::ptrdiff_t>
class any_view : public std::ranges::view_interface<any_view<ElementT, OptionsV, RefT, RValueRefT, DiffT>> {
class iterator; // exposition-only
class sentinel; // exposition-only
using size_type = /*make-unsigned-like-t*/<DiffT>; // exposition-only
static constexpr bool copyable = // exposition-only
#if BEMAN_ANY_VIEW_USE_COPYABLE()
(OptionsV & any_view_options::copyable) == any_view_options::copyable;
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
(OptionsV & any_view_options::move_only) != any_view_options::move_only;
#endif
static constexpr bool sized = // exposition-only
(OptionsV & any_view_options::sized) == any_view_options::sized;
public:
template </*viewable-range-compatible-with*/<any_view> RangeT>
constexpr any_view(RangeT&& range);
constexpr any_view(const any_view&) requires copyable;
constexpr any_view(any_view&&) noexcept;
constexpr auto operator=(const any_view&) -> any_view& requires copyable;
constexpr auto operator=(any_view&&) noexcept -> any_view&;
constexpr auto begin() -> iterator;
constexpr auto end() -> sentinel;
constexpr auto size() const -> size_type requires sized;
};
} // namespace beman::any_view
template <class ElementT, auto OptionsV, class RefT, class RValueRefT, class DiffT>
inline constexpr bool std::ranges::enable_borrowed_range<
beman::any_view::any_view<ElementT, OptionsV, RefT, RValueRefT, DiffT>> =
(OptionsV & beman::any_view::any_view_options::borrowed) == beman::any_view::any_view_options::borrowed;TRAITS
Synopsis:
#define BEMAN_ANY_VIEW_USE_ENUM() 0
#define BEMAN_ANY_VIEW_USE_TRAITS() 1
#define BEMAN_ANY_VIEW_USE_NAMED() 0
namespace beman::any_view {
struct default_range_traits {};
template <std::ranges::range RangeT>
struct range_traits {
using iterator_concept = /*range-concept-t*/<RangeT>;
using reference_type = std::ranges::range_reference_t<RangeT>;
using rvalue_reference_type = std::ranges::range_rvalue_reference_t<RangeT>;
using difference_type = std::ranges::range_difference_t<RangeT>;
static constexpr bool sized = std::ranges::sized_range<RangeT>;
static constexpr bool borrowed = std::ranges::borrowed_range<RangeT>;
#if BEMAN_ANY_VIEW_USE_COPYABLE()
static constexpr bool copyable = std::copyable<RangeT>;
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
static constexpr bool move_only = not std::copyable<RangeT>;
#endif
};
template <class ElementT, class RangeTraitsT = default_range_traits>
class any_view : public std::ranges::view_interface<any_view<ElementT, RangeTraitsT>> {
class iterator; // exposition-only
class sentinel; // exposition-only
using difference_type = /*difference-type-or-t*/<std::ptrdiff_t, RangeTraitsT>; // exposition-only
using size_type = /*make-unsigned-like-t*/<difference_type>; // exposition-only
static constexpr bool copyable = // exposition-only
#if BEMAN_ANY_VIEW_USE_COPYABLE()
/*copyable-or-v*/<false, RangeTraitsT>;
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
not /*move-only-or-v*/<false, RangeTraitsT>;
#endif
static constexpr bool sized = /*sized-or-v*/<false, RangeTraitsT>; // exposition-only
public:
template </*viewable-range-compatible-with*/<any_view> RangeT>
constexpr any_view(RangeT&& range);
constexpr any_view(const any_view&) requires copyable;
constexpr any_view(any_view&&) noexcept;
constexpr auto operator=(const any_view&) -> any_view& requires copyable;
constexpr auto operator=(any_view&&) noexcept -> any_view&;
constexpr auto begin() -> iterator;
constexpr auto end() -> sentinel;
constexpr auto size() const -> size_type requires sized;
};
} // namespace beman::any_view
template <class ElementT, class RangeTraitsT>
inline constexpr bool std::ranges::enable_borrowed_range<beman::any_view::any_view<ElementT, RangeTraitsT>> =
/*borrowed-or-v*/<false, RangeTraitsT>;NAMED
Synopsis:
#define BEMAN_ANY_VIEW_USE_ENUM() 0
#define BEMAN_ANY_VIEW_USE_TRAITS() 0
#define BEMAN_ANY_VIEW_USE_NAMED() 1
namespace beman::any_view {
template <class T>
struct type_t {
using type = T;
};
template <class T>
inline constexpr type_t<T> type{};
template <class RefT,
class IterConceptT = std::input_iterator_tag,
class RValueRefT = /*as-rvalue-t*/<RefT>,
class DiffT = std::ptrdiff_t>
struct any_view_options {
type_t<RefT> reference_type;
type_t<IterConceptT> iterator_concept = {};
bool sized = false;
#if BEMAN_ANY_VIEW_USE_COPYABLE()
bool copyable = false;
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
bool move_only = false;
#endif
bool borrowed = false;
type_t<RValueRefT> rvalue_reference_type = {};
type_t<DiffT> difference_type = {};
};
template <class ElementT, any_view_options OptionsV = {.reference_type = type<ElementT&>}>
class any_view : public std::ranges::view_interface<any_view<ElementT, OptionsV>> {
class iterator; // exposition-only
class sentinel; // exposition-only
using difference_type = decltype(OptionsV.difference_type)::type; // exposition-only
using size_type = /*make-unsigned-like-t*/<difference_type>; // exposition-only
static constexpr bool copyable = // exposition-only
#if BEMAN_ANY_VIEW_USE_COPYABLE()
OptionsV.copyable;
#elif BEMAN_ANY_VIEW_USE_MOVE_ONLY()
not OptionsV.move_only;
#endif
static constexpr bool sized = OptionsV.sized; // exposition-only
public:
template </*viewable-range-compatible-with*/<any_view> RangeT>
constexpr any_view(RangeT&& range);
constexpr any_view(const any_view&) requires copyable;
constexpr any_view(any_view&&) noexcept;
constexpr auto operator=(const any_view&) -> any_view& requires copyable;
constexpr auto operator=(any_view&&) noexcept -> any_view&;
constexpr auto begin() -> iterator;
constexpr auto end() -> sentinel;
constexpr auto size() const -> size_type requires sized;
};
} // namespace beman::any_view
template <class ElementT, auto OptionsV>
inline constexpr bool std::ranges::enable_borrowed_range<beman::any_view::any_view<ElementT, OptionsV>> =
OptionsV.borrowed;COPYABLE (default)
Synopsis:
#define BEMAN_ANY_VIEW_USE_COPYABLE() 1
#define BEMAN_ANY_VIEW_USE_MOVE_ONLY() 0MOVE_ONLY
Synopsis:
#define BEMAN_ANY_VIEW_USE_COPYABLE() 0
#define BEMAN_ANY_VIEW_USE_MOVE_ONLY() 1-DBEMAN_ANY_VIEW_DESIGN=ENUM
-DBEMAN_ANY_VIEW_DESIGN=TRAITS
-DBEMAN_ANY_VIEW_DESIGN=NAMED
-DBEMAN_ANY_VIEW_OPTION=COPYABLE
-DBEMAN_ANY_VIEW_OPTION=MOVE_ONLY
There are workflows available in CMake presets such as gcc-debug:
cmake --workflow --preset gcc-debugAlternatively you can manually configure, build, and test with CMake and CTest:
cmake -B build
cmake --build build
ctest --test-dir buildPossible output:
Executing workflow step 1 of 3: configure preset "gcc-debug"
Preset CMake variables:
BEMAN_BUILDSYS_SANITIZER="MaxSan"
CMAKE_BUILD_TYPE="Debug"
CMAKE_EXPORT_COMPILE_COMMANDS:BOOL="TRUE"
CMAKE_TOOLCHAIN_FILE="cmake/gnu-toolchain.cmake"
-- The CXX compiler identification is GNU 15.0.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- The C compiler identification is GNU 15.0.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Found Python3: /usr/bin/python3.12 (found version "3.12.7") found components: Interpreter
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Configuring done (2.7s)
-- Generating done (0.0s)
-- Build files have been written to: /home/patrick/projects/any_view/build/gcc-debug
Executing workflow step 2 of 3: build preset "gcc-debug"
[12/12] Linking CXX executable tests/beman/any_view/beman.any_view.tests.constexpr
Executing workflow step 3 of 3: test preset "gcc-debug"
Test project /home/patrick/projects/any_view/build/gcc-debug
Start 1: ConceptsTest.iterator_concept
1/21 Test #1: ConceptsTest.iterator_concept ................... Passed 0.01 sec
Start 2: ConceptsTest.sized_concept
2/21 Test #2: ConceptsTest.sized_concept ...................... Passed 0.01 sec
Start 3: ConceptsTest.borrowed_concept
3/21 Test #3: ConceptsTest.borrowed_concept ................... Passed 0.01 sec
Start 4: ConceptsTest.copyable_concept
4/21 Test #4: ConceptsTest.copyable_concept ................... Passed 0.01 sec
Start 5: ConstexprTest.sum_vector_of_vector
5/21 Test #5: ConstexprTest.sum_vector_of_vector .............. Passed 0.01 sec
Start 6: ConstexprTest.sum_transform_view_of_iota_view
6/21 Test #6: ConstexprTest.sum_transform_view_of_iota_view ... Passed 0.01 sec
Start 7: ConstexprTest.sum_vector_of_iota_view
7/21 Test #7: ConstexprTest.sum_vector_of_iota_view ........... Passed 0.01 sec
Start 8: ConstexprTest.sort_vector
8/21 Test #8: ConstexprTest.sort_vector ....................... Passed 0.01 sec
Start 9: SfinaeTest.istream_view
9/21 Test #9: SfinaeTest.istream_view ......................... Passed 0.01 sec
Start 10: SfinaeTest.forward_list
10/21 Test #10: SfinaeTest.forward_list ......................... Passed 0.01 sec
Start 11: SfinaeTest.list
11/21 Test #11: SfinaeTest.list ................................. Passed 0.01 sec
Start 12: SfinaeTest.deque
12/21 Test #12: SfinaeTest.deque ................................ Passed 0.01 sec
Start 13: SfinaeTest.vector
13/21 Test #13: SfinaeTest.vector ............................... Passed 0.01 sec
Start 14: SfinaeTest.vector_of_bool
14/21 Test #14: SfinaeTest.vector_of_bool ....................... Passed 0.01 sec
Start 15: SfinaeTest.span
15/21 Test #15: SfinaeTest.span ................................. Passed 0.01 sec
Start 16: TypeTraitsTest.value_type
16/21 Test #16: TypeTraitsTest.value_type ....................... Passed 0.01 sec
Start 17: TypeTraitsTest.reference_type
17/21 Test #17: TypeTraitsTest.reference_type ................... Passed 0.01 sec
Start 18: TypeTraitsTest.rvalue_reference_type
18/21 Test #18: TypeTraitsTest.rvalue_reference_type ............ Passed 0.01 sec
Start 19: TypeTraitsTest.difference_type
19/21 Test #19: TypeTraitsTest.difference_type .................. Passed 0.01 sec
Start 20: TypeTraitsTest.size_type
20/21 Test #20: TypeTraitsTest.size_type ........................ Passed 0.01 sec
Start 21: TypeTraitsTest.borrowed_iterator_type
21/21 Test #21: TypeTraitsTest.borrowed_iterator_type ........... Passed 0.01 sec
100% tests passed, 0 tests failed out of 21
Total Test time (real) = 0.15 sec
Please do! Issues and pull requests are appreciated.