Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::stl_interfaces::v1::view_interface
// In header: <boost/stl_interfaces/view_interface.hpp> template<typename Derived, element_layout Contiguity> struct view_interface { // public member functions template<typename D = Derived> constexpr auto empty() noexcept(noexcept(std::declval< D & >().begin()==std::declval< D & >().end()))); template<typename D = Derived> constexpr auto empty() const noexcept(noexcept(std::declval< D const & >().begin()==std::declval< D const & >().end()))); template<typename D = Derived, typename R = decltype(std::declval<D &>().empty())> explicit constexpr operator bool() noexcept(noexcept(std::declval< D & >().empty()))); template<typename D = Derived, typename R = decltype(std::declval<D const &>().empty())> explicit constexpr operator bool() const noexcept(noexcept(std::declval< D const & >().empty()))); template<typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous> > constexpr auto data() noexcept(noexcept(std::declval< D & >().begin()))); template<typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous> > constexpr auto data() const noexcept(noexcept(std::declval< D const & >().begin()))); template<typename D = Derived> constexpr auto size() noexcept(noexcept(std::declval< D & >().end() - std::declval< D & >().begin()))); template<typename D = Derived> constexpr auto size() const noexcept(noexcept(std::declval< D const & >().end() - std::declval< D const & >().begin()))); template<typename D = Derived> constexpr auto front() noexcept(noexcept(*std::declval< D & >().begin()))); template<typename D = Derived> constexpr auto front() const noexcept(noexcept(*std::declval< D const & >().begin()))); template<typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value> > constexpr auto back() noexcept(noexcept(*std::prev(std::declval< D & >().end())))); template<typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value> > constexpr auto back() const noexcept(noexcept(*std::prev(std::declval< D const & >().end())))); template<typename D = Derived> constexpr auto operator[](v1_dtl::range_difference_t< D >) noexcept(noexcept(std::declval< D & >().begin()[n]))); template<typename D = Derived> constexpr auto operator[](v1_dtl::range_difference_t< D >) const noexcept(noexcept(std::declval< D const & >().begin()[n]))); };
A CRTP template that one may derive from to make it easier to define std::ranges::view-like types with a container-like interface. This is a pre-C++20 version of C++20's view_interface (see [view.interface] in the C++ standard).
The template parameter D for view_interface may be an incomplete type. Before any member of the resulting specialization of view_interface other than special member functions is referenced, D shall be complete, and model both std::derived_from<view_interface<D>> and std::view.
view_interface public member functionstemplate<typename D = Derived> constexpr auto empty() noexcept(noexcept(std::declval< D & >().begin()==std::declval< D & >().end())));
template<typename D = Derived> constexpr auto empty() const noexcept(noexcept(std::declval< D const & >().begin()==std::declval< D const & >().end())));
template<typename D = Derived, typename R = decltype(std::declval<D &>().empty())> explicit constexpr operator bool() noexcept(noexcept(std::declval< D & >().empty())));
template<typename D = Derived, typename R = decltype(std::declval<D const &>().empty())> explicit constexpr operator bool() const noexcept(noexcept(std::declval< D const & >().empty())));
template<typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous> > constexpr auto data() noexcept(noexcept(std::declval< D & >().begin())));
template<typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous> > constexpr auto data() const noexcept(noexcept(std::declval< D const & >().begin())));
template<typename D = Derived> constexpr auto size() noexcept(noexcept(std::declval< D & >().end() - std::declval< D & >().begin())));
template<typename D = Derived> constexpr auto size() const noexcept(noexcept(std::declval< D const & >().end() - std::declval< D const & >().begin())));
template<typename D = Derived> constexpr auto front() noexcept(noexcept(*std::declval< D & >().begin())));
template<typename D = Derived> constexpr auto front() const noexcept(noexcept(*std::declval< D const & >().begin())));
template<typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value> > constexpr auto back() noexcept(noexcept(*std::prev(std::declval< D & >().end()))));
template<typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value> > constexpr auto back() const noexcept(noexcept(*std::prev(std::declval< D const & >().end()))));
template<typename D = Derived> constexpr auto operator[](v1_dtl::range_difference_t< D > n) noexcept(noexcept(std::declval< D & >().begin()[n])));
template<typename D = Derived> constexpr auto operator[](v1_dtl::range_difference_t< D > n) const noexcept(noexcept(std::declval< D const & >().begin()[n])));