curl_slist.hpp

#ifndef  __curl_cpp_utils_curl_slist_HPP__
# define __curl_cpp_utils_curl_slist_HPP__
 
# include <cstddef>
# include <memory>
# include <iterator>
 
# include "../return-exception/ret-exception.hpp"
 
namespace curl::utils {
/**
 * Container wrapper for curl's struct curl_slist,
 * which is a single-linked list storing
 * string.
 *
 * Thread-safety:
 *  - If all threads access only const member function, then it is thread-safe;
 *  - Only one thread can call non-const member function at a time;
 *  - If another thread is modifing this class, other reader should wait until it is done.
 */
class slist {
protected:
    void *list = nullptr;
 
public:
    using value_type = const char*;
 
    using size_type = std::size_t;
    using difference_type = std::ptrdiff_t;
 
    using reference = value_type&;
    using const_reference = const value_type&;
 
    using pointer = value_type*;
    using const_pointer = const value_type*;
 
    struct const_iterator {
        const void *list_ptr = nullptr;
 
        using value_type = slist::value_type;
        using pointer = value_type*;
        using reference = value_type&;
        using difference_type = std::ptrdiff_t;
        using iterator_category = std::forward_iterator_tag;
 
        auto operator ++ () noexcept -> const_iterator&;
        auto operator ++ (int) noexcept -> const_iterator;
 
        auto operator * () const noexcept -> value_type;
 
        friend bool operator == (const const_iterator &x, const const_iterator &y) noexcept;
        friend bool operator != (const const_iterator &x, const const_iterator &y) noexcept;
    };
 
    slist() = default;
 
    slist(void *l) noexcept;
 
    slist(const slist&) = delete;
    slist(slist &&other) noexcept;
 
    slist& operator = (const slist&) = delete;
    slist& operator = (slist &&other) noexcept;
 
    void swap(slist &other) noexcept;
    /**
     * Free all elements stored in the slist and the slist
     * itself.
     *
     * Set protected member slist::list to nullptr.
     */
    void clear() noexcept;
 
    ~slist();
 
    bool is_empty() const noexcept;
 
    auto begin() const noexcept -> const_iterator;
    auto end() const noexcept -> const_iterator;
 
    auto cbegin() const noexcept -> const_iterator;
    auto cend() const noexcept -> const_iterator;
 
    /**
     * Get underlying struct curl_slist* pointer.
     */
    auto get_underlying_ptr() const noexcept -> void*;
 
    /**
     * @param str is dupped before adding to the list.
     *            Must not be CRLF-terminated for use in curl::Easy_ref_t::set_http_header.
     */
    auto push_back(const char *str) noexcept -> Ret_except<void, std::bad_alloc>;
};
} /* namespace curl::utils */
 
#endif