utils.hpp - master - anenkov/CppUtils

utils.hpp
68 строк2 KB
Aleksandr Anenkov
Fix exception type
01 авг 2024, 01:25
01 авг 2024, 01:25f12b5f4
#include <source_location>
#include <stdexcept>
#include <string>
#include <ranges>

#define throw_with_message_if_not(cond, msg)             \
    if (cond) [[likely]]                                 \
        static_cast<void>(0);                            \
    else                                                 \
        std::throw_with_nested(std::logic_error(msg))    \


#define throw_if_not(cond) \
    throw_with_message_if_not(cond, "Condition failed: "#cond" in " + std::string(std::source_location::current().function_name()));


namespace utils
{

template <class R, class V>
concept view_of = std::ranges::input_range<R> && (std::same_as<std::ranges::range_value_t<R>, V> || std::convertible_to<std::ranges::range_value_t<R>, const V&>);

template <class T>
concept is_comparable_to_pointer = requires(T a)
{
    { std::declval<T>() != nullptr };
};

template <class T>
class not_null
{
public:
    static_assert(is_comparable_to_pointer<T>, "Type is not convertibe to a pointer");

    constexpr not_null(std::nullptr_t) = delete;
    constexpr not_null& operator=(std::nullptr_t) = delete;
    constexpr not_null(const not_null<T>&) = default;
    constexpr not_null(not_null<T>&&) noexcept(std::is_nothrow_move_constructible_v<not_null<T>>) = default;
    constexpr not_null& operator=(const not_null<T>&) = default;
    constexpr not_null& operator=(not_null<T>&&) noexcept = default;

    constexpr not_null(T t) : m_ptr{std::forward<T>(t)} {
        check();
    }

    template <class U>
        requires (std::is_convertible_v<T, U>)
    constexpr not_null(U u) : m_ptr{std::forward<U>(u)} {
        check();
    }

    [[nodiscard]] constexpr T get() const noexcept { return m_ptr; }

    constexpr operator T() const { return get(); }
    constexpr auto operator->() const { return get(); }
    [[nodiscard]] constexpr auto operator*() const { return *get(); }

private:
    T m_ptr;

    constexpr void check() const {
        if (!m_ptr) [[unlikely]] {
            throw std::logic_error("pointer is nullptr");
        }
    }
};

}