gistfile1.txt

    //------------------------------------------------------
    //
    // fragment
    //
    //------------------------------------------------------

    /** Return the fragment.

        This function returns the fragment of the URL:

        * If a fragment is present, it is returned in
        decoded form without a leading hash mark ('#'),
        otherwise:

        * If there is no fragment, an empty string is
        returned.

        Note that if the URL contains a hash mark
        followed by an empty query string, this
        function still returns an empty string.
        detect this case, use @ref fragment_part
        instead.

        @par Exception Safety

        Strong guarantee.
        Calls to allocate may throw.

        @param a An optional allocator the returned
        string will use. If this parameter is omitted,
        the default allocator is used, and the return
        type of the function becomes `std::string`.

        @return A `std::basic_string` using the
        specified allocator.

        @see encoded_fragment, fragment_part
    */
    template<
        class Allocator =
            std::allocator<char>>
    string_type<Allocator>
    fragment(
        Allocator const& a = {}) const
    {
        return detail::decode(
            encoded_fragment(), a);
    }

    /** Return the fragment.

        This function returns the fragment of the URL:

        * If a fragment is present, it is returned in
        encoded form without a leading hash mark ('#'),
        otherwise:

        * If there is no fragment, an empty string is
        returned.

        Note that if the URL contains a hash mark
        followed by an empty query string, this
        function still returns an empty string.
        detect this case, use @ref fragment_part
        instead.

        @par Exception Safety

        No-throw guarantee.

        @param a An optional allocator the returned
        string will use. If this parameter is omitted,
        the default allocator is used, and the return
        type of the function becomes `std::string`.

        @return A `std::basic_string` using the
        specified allocator.

        @see fragment, fragment_part
    */
    BOOST_URL_DECL
    string_view
    encoded_fragment() const noexcept;

    /** Return the fragment.

        This function returns the fragment of the URL:

        * If a fragment is present, it is returned
        in encoded form including the leading hash
        mark ('#'), otherwise:

        * If there is no fragment, an empty string is
        returned.

        Note that if the URL contains a hash mark
        followed by an empty query string, this
        function returns "#".

        @par Exception Safety

        No-throw guarantee.

        @see fragment, encoded_fragment
    */
    BOOST_URL_DECL
    string_view
    fragment_part() const noexcept;

    /** Set the fragment.

        Sets the fragment of the URL to the specified
        plain string:

        @li If the string is empty, the fragment is
        cleared including the leading hash mark ('#'),
        otherwise:

        @li If the string is not empty, the fragment
        is set to given string, with a leading hash
        mark added.
        Any special or reserved characters in the
        string are automatically percent-encoded.

        @par Exception Safety

        Strong guarantee.
        Calls to allocate may throw.

        @param s The string to set. This string may
        contain any characters, including nulls.
    */
    BOOST_URL_DECL
    basic_value&
    set_fragment(
        string_view s);

    /** Set the fragment.

        Sets the fragment of the URL to the specified
        encoded string:

        @li If the string is empty, the fragment is
        cleared including the leading hash mark ('#'),
        otherwise:

        @li If the string is not empty, the fragment
        is set to given string, with a leading hash
        mark added.
        The string must meet the syntactic requirements
        of <em>fragment</em> otherwise an exception is
        thrown.

        @par ABNF
        @code
        fragment      = *( pchar / "/" / "?" )
        @endcode

        @par Exception Safety

        Strong guarantee.
        Calls to allocate may throw.

        @param s The string to set.

        @throws std::exception invalid string.
    */
    BOOST_URL_DECL
    basic_value&
    set_encoded_fragment(
        string_view s);

    /** Set the fragment.

        Sets the fragment of the URL to the specified
        encoded string.

        @li If the string is empty, the fragment is
        cleared including the leading hash mark ('#'),
        otherwise:
        
        @li If the string is not empty, the fragment
        is set to given string.
        The string must meet the syntactic requirements
        of <em>fragment-part</em> otherwise an exception
        is thrown.

        @par ABNF
        @code
        fragment-part = "#" *( pchar / "/" / "?" )
        @endcode

        @par Exception Safety

        Strong guarantee.
        Calls to allocate may throw.

        @param s The string to set.

        @throws std::exception invalid string.
    */
    BOOST_URL_DECL
    basic_value&
    set_fragment_part(
        string_view s);