memory.hpp

#ifndef TOPAZ_CORE_MEMORY_HPP
#define TOPAZ_CORE_MEMORY_HPP
#include <span>
#include <ranges>
#include <type_traits>
 
namespace tz
{
    template<typename T>
    constexpr auto view_bytes(T&& t) -> std::conditional_t<std::is_const_v<T>, std::span<const std::byte>, std::span<std::byte>>
    {
        if constexpr(requires{std::ranges::contiguous_range<T>;})
        {
            // we are a range   
            using V = std::ranges::range_value_t<T>;
            std::span<V> range{std::begin(t), std::end(t)};
            if constexpr(std::is_const_v<V>)
            {
                return std::as_bytes(range);
            }
            else
            {
                return std::as_writable_bytes(range);
            }
        }
        else
        {
            // we are not a range
            static_assert(std::is_standard_layout_v<T>, "view_bytes must be provided a contiguous range or a standard-layout-type. You have provided neither.");
            // we are a scalar-y value
            std::span<T, 1> span{&t};
            if constexpr(std::is_const_v<T>)
            {
                return std::as_bytes(span);
            }
            else
            {
                return std::as_writable_bytes(span);
            }
        }
    }
}
 
#endif // TOPAZ_CORE_MEMORY_HPP