vector_view.hpp

/* VecMem project, part of the ACTS project (R&D line)
 *
 * (c) 2021-2025 CERN for the benefit of the ACTS project
 *
 * Mozilla Public License Version 2.0
 */
#pragma once
 
// Local include(s).
#include "vecmem/utils/type_traits.hpp"
#include "vecmem/utils/types.hpp"
 
// System include(s).
#include <cstddef>
#include <type_traits>
 
namespace vecmem {
 
namespace data {
 
template <typename TYPE>
class vector_view {
 
    static_assert(
        !std::is_same<typename std::remove_cv<TYPE>::type, bool>::value,
        "bool is not supported in VecMem containers");
 
public:
    using size_type = unsigned int;
    using size_pointer =
        std::conditional_t<std::is_const<TYPE>::value,
                           std::add_pointer_t<std::add_const_t<size_type>>,
                           std::add_pointer_t<size_type>>;
    using pointer = std::add_pointer_t<TYPE>;
 
    vector_view() = default;
    VECMEM_HOST_AND_DEVICE
    vector_view(size_type size, pointer ptr);
    VECMEM_HOST_AND_DEVICE
    vector_view(size_type capacity, size_pointer size, pointer ptr);
 
    template <typename OTHERTYPE,
              std::enable_if_t<details::is_same_nc<TYPE, OTHERTYPE>::value,
                               bool> = true>
    VECMEM_HOST_AND_DEVICE vector_view(const vector_view<OTHERTYPE>& parent);
 
    template <typename OTHERTYPE,
              std::enable_if_t<details::is_same_nc<TYPE, OTHERTYPE>::value,
                               bool> = true>
    VECMEM_HOST_AND_DEVICE vector_view& operator=(
        const vector_view<OTHERTYPE>& rhs);
 
    template <typename OTHERTYPE,
              std::enable_if_t<std::is_same<std::remove_cv_t<TYPE>,
                                            std::remove_cv_t<OTHERTYPE>>::value,
                               bool> = true>
    VECMEM_HOST_AND_DEVICE bool operator==(
        const vector_view<OTHERTYPE>& rhs) const;
 
    template <typename OTHERTYPE,
              std::enable_if_t<std::is_same<std::remove_cv_t<TYPE>,
                                            std::remove_cv_t<OTHERTYPE>>::value,
                               bool> = true>
    VECMEM_HOST_AND_DEVICE bool operator!=(
        const vector_view<OTHERTYPE>& rhs) const;
 
    VECMEM_HOST_AND_DEVICE
    size_type size() const;
    VECMEM_HOST_AND_DEVICE
    size_type capacity() const;
 
    VECMEM_HOST_AND_DEVICE
    size_pointer size_ptr() const;
 
    VECMEM_HOST_AND_DEVICE
    pointer ptr() const;
 
private:
    size_type m_capacity;
    size_pointer m_size;
    pointer m_ptr;
 
};  // struct vector_view
 
}  // namespace data
}  // namespace vecmem
 
// Include the implementation.
#include "vecmem/containers/impl/vector_view.ipp"