pointers.h

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 * VCLib                                                                     *
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 * Copyright(C) 2021-2025                                                    *
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#ifndef VCL_VIEWS_POINTERS_H
#define VCL_VIEWS_POINTERS_H
 
#include <ranges>
 
namespace vcl::views {
 
namespace detail {
 
struct NotNullView
{
    constexpr NotNullView() = default;
 
    template<std::ranges::range R>
    friend constexpr auto operator|(R&& r, NotNullView)
    {
        return std::views::filter(r, [](auto* p) {
            return p != nullptr;
        });
    }
};
 
struct DereferenceView
{
    constexpr DereferenceView() = default;
 
    template<std::ranges::range R>
    friend constexpr auto operator|(R&& r, DereferenceView)
    {
        return std::views::transform(r, [](auto p) {
            return *p;
        });
    }
};
 
struct AddressOfView
{
    constexpr AddressOfView() = default;
 
    template<std::ranges::range R>
    friend constexpr auto operator|(R&& r, AddressOfView)
    {
        return std::views::transform(r, [](auto& o) {
            return &o;
        });
    }
};
 
struct ConstAddressOfView
{
    constexpr ConstAddressOfView() = default;
 
    template<std::ranges::range R>
    friend constexpr auto operator|(R&& r, ConstAddressOfView)
    {
        return std::views::transform(r, [](const auto& o) {
            return &o;
        });
    }
};
 
} // namespace detail
 
inline constexpr detail::NotNullView notNull;
 
inline constexpr detail::DereferenceView deref;
 
inline constexpr detail::AddressOfView addrOf;
 
inline constexpr detail::ConstAddressOfView constAddrOf;
 
} // namespace vcl::views
 
#endif // VCL_VIEWS_POINTERS_H