Added thirdparty: boost library

thirdparty/include/boost/url/decode_view.hpp

@@ -0,0 +1,697 @@
+//
+// Copyright (c) 2022 Alan de Freitas (alandefreitas@gmail.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/boostorg/url
+//
+
+#ifndef BOOST_URL_DECODE_VIEW_HPP
+#define BOOST_URL_DECODE_VIEW_HPP
+
+#include <boost/url/detail/config.hpp>
+#include <boost/core/detail/string_view.hpp>
+#include <boost/url/encoding_opts.hpp>
+#include <boost/url/pct_string_view.hpp>
+#include <type_traits>
+#include <iterator>
+#include <iosfwd>
+
+namespace boost {
+namespace urls {
+
+//------------------------------------------------
+
+#ifndef BOOST_URL_DOCS
+class decode_view;
+
+namespace detail {
+
+// unchecked
+template<class... Args>
+decode_view
+make_decode_view(
+    Args&&... args) noexcept;
+
+} // detail
+#endif
+
+//------------------------------------------------
+
+/** A reference to a valid, percent-encoded string
+
+    These views reference strings in parts of URLs
+    or other components that are percent-encoded.
+    The special characters (those not in the
+    allowed character set) are stored as three
+    character escapes that consist of a percent
+    sign ('%%') followed by a two-digit hexadecimal
+    number of the corresponding unescaped character
+    code, which may be part of a UTF-8 code point
+    depending on the context.
+
+    The view refers to the original character
+    buffer and only decodes escaped sequences when
+    needed. In particular these operations perform
+    percent-decoding automatically without the
+    need to allocate memory:
+
+    @li Iteration of the string
+    @li Accessing the encoded character buffer
+    @li Comparison to encoded or plain strings
+
+    These objects can only be constructed from
+    strings that have a valid percent-encoding,
+    otherwise construction fails. The caller is
+    responsible for ensuring that the lifetime
+    of the character buffer from which the view
+    is constructed extends unmodified until the
+    view is no longer accessed.
+
+    @par Operators
+    The following operators are supported between
+    @ref decode_view and any object that is convertible
+    to `core::string_view`
+
+    @code
+    bool operator==( decode_view, decode_view ) noexcept;
+    bool operator!=( decode_view, decode_view ) noexcept;
+    bool operator<=( decode_view, decode_view ) noexcept;
+    bool operator< ( decode_view, decode_view ) noexcept;
+    bool operator> ( decode_view, decode_view ) noexcept;
+    bool operator>=( decode_view, decode_view ) noexcept;
+    @endcode
+
+*/
+class decode_view
+{
+    char const* p_ = nullptr;
+    std::size_t n_ = 0;
+    std::size_t dn_ = 0;
+    bool space_as_plus_ = true;
+
+#ifndef BOOST_URL_DOCS
+    template<class... Args>
+    friend
+    decode_view
+    detail::make_decode_view(
+        Args&&... args) noexcept;
+#endif
+
+    // unchecked
+    BOOST_URL_DECL
+    explicit
+    decode_view(
+        core::string_view s,
+        std::size_t n,
+        encoding_opts opt) noexcept;
+
+public:
+    /** The value type
+    */
+    using value_type = char;
+
+    /** The reference type
+    */
+    using reference = char;
+
+    /// @copydoc reference
+    using const_reference = char;
+
+    /** The unsigned integer type
+    */
+    using size_type = std::size_t;
+
+    /** The signed integer type
+    */
+    using difference_type = std::ptrdiff_t;
+
+    /** An iterator of constant, decoded characters.
+
+        This iterator is used to access the encoded
+        string as a bidirectional range of characters
+        with percent-decoding applied. Escape sequences
+        are not decoded until the iterator is
+        dereferenced.
+    */
+#ifdef BOOST_URL_DOCS
+    using iterator = __see_below__;
+#else
+    class iterator;
+#endif
+
+    /// @copydoc iterator
+    using const_iterator = iterator;
+
+    //--------------------------------------------
+    //
+    // Special Members
+    //
+    //--------------------------------------------
+
+    /** Constructor
+
+        Default-constructed views represent
+        empty strings.
+
+        @par Example
+        @code
+        decode_view ds;
+        @endcode
+
+        @par Postconditions
+        @code
+        this->empty() == true
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    decode_view() noexcept = default;
+
+    /** Constructor
+
+        This constructs a view from the character
+        buffer `s`, which must remain valid and
+        unmodified until the view is no longer
+        accessed.
+
+        @par Example
+        @code
+        decode_view ds( "Program%20Files" );
+        @endcode
+
+        @par Postconditions
+        @code
+        this->encoded() == s
+        @endcode
+
+        @par Complexity
+        Linear in `s.size()`.
+
+        @par Exception Safety
+        Exceptions thrown on invalid input.
+
+        @throw system_error
+        The string contains an invalid percent encoding.
+
+        @param s A percent-encoded string that has
+        already been validated.
+
+        @param opt The options for decoding. If
+        this parameter is omitted, the default
+        options are used.
+    */
+    explicit
+    decode_view(
+        pct_string_view s,
+        encoding_opts opt = {}) noexcept
+        : decode_view(
+            detail::to_sv(s),
+            s.decoded_size(),
+            opt)
+    {
+    }
+
+    //--------------------------------------------
+    //
+    // Observers
+    //
+    //--------------------------------------------
+
+    /** Return true if the string is empty
+
+        @par Example
+        @code
+        assert( decode_view( "" ).empty() );
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    bool
+    empty() const noexcept
+    {
+        return n_ == 0;
+    }
+
+    /** Return the number of decoded characters
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).size() == 13 );
+        @endcode
+
+        @par Effects
+        @code
+        return std::distance( this->begin(), this->end() );
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    size_type
+    size() const noexcept
+    {
+        return dn_;
+    }
+
+    /** Return an iterator to the beginning
+
+        @par Example
+        @code
+        auto it = this->begin();
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    iterator
+    begin() const noexcept;
+
+    /** Return an iterator to the end
+
+        @par Example
+        @code
+        auto it = this->end();
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    iterator
+    end() const noexcept;
+
+    /** Return the first character
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).front() == 'P' );
+        @endcode
+
+        @par Preconditions
+        @code
+        not this->empty()
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    reference
+    front() const noexcept;
+
+    /** Return the last character
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).back() == 's' );
+        @endcode
+
+        @par Preconditions
+        @code
+        not this->empty()
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    reference
+    back() const noexcept;
+
+    /** Checks if the string begins with the given prefix
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).starts_with("Program") );
+        @endcode
+
+        @par Complexity
+        Linear.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    bool
+    starts_with( core::string_view s ) const noexcept;
+
+    /** Checks if the string ends with the given prefix
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).ends_with("Files") );
+        @endcode
+
+        @par Complexity
+        Linear.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    bool
+    ends_with( core::string_view s ) const noexcept;
+
+    /** Checks if the string begins with the given prefix
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).starts_with('P') );
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    bool
+    starts_with( char ch ) const noexcept;
+
+    /** Checks if the string ends with the given prefix
+
+        @par Example
+        @code
+        assert( decode_view( "Program%20Files" ).ends_with('s') );
+        @endcode
+
+        @par Complexity
+        Constant.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    bool
+    ends_with( char ch ) const noexcept;
+
+    /** Finds the first occurrence of character in this view
+
+        @par Complexity
+        Linear.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    const_iterator
+    find( char ch ) const noexcept;
+
+    /** Finds the first occurrence of character in this view
+
+        @par Complexity
+        Linear.
+
+        @par Exception Safety
+        Throws nothing.
+    */
+    BOOST_URL_DECL
+    const_iterator
+    rfind( char ch ) const noexcept;
+
+    /** Remove the first characters
+
+        @par Example
+        @code
+        decode_view d( "Program%20Files" );
+        d.remove_prefix( 8 );
+        assert( d == "Files" );
+        @endcode
+
+        @par Preconditions
+        @code
+        not this->empty()
+        @endcode
+
+        @par Complexity
+        Linear.
+    */
+    BOOST_URL_DECL
+    void
+    remove_prefix( size_type n );
+
+    /** Remove the last characters
+
+        @par Example
+        @code
+        decode_view d( "Program%20Files" );
+        d.remove_prefix( 6 );
+        assert( d == "Program" );
+        @endcode
+
+        @par Preconditions
+        @code
+        not this->empty()
+        @endcode
+
+        @par Complexity
+        Linear.
+    */
+    BOOST_URL_DECL
+    void
+    remove_suffix( size_type n );
+
+    /** Return the decoding options
+    */
+    encoding_opts
+    options() const noexcept
+    {
+        encoding_opts opt;
+        opt.space_as_plus = space_as_plus_;
+        return opt;
+    }
+
+    //--------------------------------------------
+    //
+    // Comparison
+    //
+    //--------------------------------------------
+
+    /** Return the result of comparing to another string
+
+        The length of the sequences to compare is the smaller of
+        `size()` and `other.size()`.
+
+        The function compares the two strings as if by calling
+        `char_traits<char>::compare(to_string().data(), v.data(), rlen)`.
+        This means the comparison is performed with
+        percent-decoding applied to the current string.
+
+        @param other string to compare
+
+        @return Negative value if this string is less than the other
+        character sequence, zero if the both character sequences are
+        equal, positive value if this string is greater than the other
+        character sequence
+    */
+    BOOST_URL_DECL
+    int
+    compare(core::string_view other) const noexcept;
+
+    /** Return the result of comparing to another string
+
+        The length of the sequences to compare is the smaller of
+        `size()` and `other.size()`.
+
+        The function compares the two strings as if by calling
+        `char_traits<char>::compare(to_string().data(), v.to_string().data(), rlen)`.
+        This means the comparison is performed with
+        percent-decoding applied to the current string.
+
+        @param other string to compare
+
+        @return Negative value if this string is less than the other
+        character sequence, zero if the both character sequences are
+        equal, positive value if this string is greater than the other
+        character sequence
+    */
+    BOOST_URL_DECL
+    int
+    compare(decode_view other) const noexcept;
+
+    //--------------------------------------------
+
+    // relational operators
+#ifndef BOOST_URL_DOCS
+private:
+    template<class S0, class S1>
+    using is_match = std::integral_constant<bool,
+        // both decode_view or convertible to core::string_view
+        (
+            std::is_same<typename std::decay<S0>::type, decode_view>::value ||
+            std::is_convertible<S0, core::string_view>::value) &&
+        (
+            std::is_same<typename std::decay<S1>::type, decode_view>::value ||
+            std::is_convertible<S1, core::string_view>::value) &&
+        // not both are convertible to string view
+        (
+            !std::is_convertible<S0, core::string_view>::value ||
+            !std::is_convertible<S1, core::string_view>::value)>;
+
+    static
+    int
+    decode_compare(decode_view s0, decode_view s1) noexcept
+    {
+        return s0.compare(s1);
+    }
+
+    template <class S>
+    static
+    int
+    decode_compare(decode_view s0, S const& s1) noexcept
+    {
+        return s0.compare(s1);
+    }
+
+    template <class S>
+    static
+    int
+    decode_compare(S const& s0, decode_view s1) noexcept
+    {
+        return -s1.compare(s0);
+    }
+public:
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator==(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) == 0;
+    }
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator!=(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) != 0;
+    }
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator<(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) < 0;
+    }
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator<=(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) <= 0;
+    }
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator>(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) > 0;
+    }
+
+    template<class S0, class S1>
+    BOOST_CXX14_CONSTEXPR friend auto operator>=(
+        S0 const& s0, S1 const& s1) noexcept ->
+        typename std::enable_if<
+            is_match<S0, S1>::value, bool>::type
+    {
+        return decode_compare(s0, s1) >= 0;
+    }
+#endif
+
+    // hidden friend
+    friend
+    std::ostream&
+    operator<<(
+        std::ostream& os,
+        decode_view const& s)
+    {
+        // hidden friend
+        s.write(os);
+        return os;
+    }
+
+private:
+    BOOST_URL_DECL
+    void
+    write(std::ostream& os) const;
+};
+
+/** Format the string with percent-decoding applied to the output stream
+
+    This function serializes the decoded view
+    to the output stream.
+
+    @return A reference to the output stream, for chaining
+
+    @param os The output stream to write to
+
+    @param s The decoded view to write
+*/
+inline
+std::ostream&
+operator<<(
+    std::ostream& os,
+    decode_view const& s);
+
+//------------------------------------------------
+
+inline
+decode_view
+pct_string_view::operator*() const noexcept
+{
+    return decode_view(*this);
+}
+
+#ifndef BOOST_URL_DOCS
+namespace detail {
+template<class... Args>
+decode_view
+make_decode_view(
+    Args&&... args) noexcept
+{
+    return decode_view(
+        std::forward<Args>(args)...);
+}
+} // detail
+#endif
+
+//------------------------------------------------
+
+} // urls
+} // boost
+
+#include <boost/url/impl/decode_view.hpp>
+
+#endif