TLA  Line data    Source code

       1                 : //
       2                 : // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
       3                 : //
       4                 : // Distributed under the Boost Software License, Version 1.0. (See accompanying
       5                 : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
       6                 : //
       7                 : // Official repository: https://github.com/cppalliance/capy
       8                 : //
       9                 : 
      10                 : #ifndef BOOST_CAPY_COND_HPP
      11                 : #define BOOST_CAPY_COND_HPP
      12                 : 
      13                 : #include <boost/capy/detail/config.hpp>
      14                 : #include <system_error>
      15                 : 
      16                 : namespace boost {
      17                 : namespace capy {
      18                 : 
      19                 : /** Portable error conditions for capy I/O operations.
      20                 : 
      21                 :     These are the conditions callers should compare against when
      22                 :     handling errors from capy operations. The @ref error enum values
      23                 :     map to these conditions, as do platform-specific error codes
      24                 :     (e.g., `ECANCELED`, SSL EOF errors).
      25                 : 
      26                 :     @par Example
      27                 : 
      28                 :     @code
      29                 :     auto [ec, n] = co_await stream.read_some( bufs );
      30                 :     if( ec == cond::canceled )
      31                 :         // handle cancellation
      32                 :     else if( ec == cond::eof )
      33                 :         // handle end of stream
      34                 :     else if( ec )
      35                 :         // handle other errors
      36                 :     @endcode
      37                 : 
      38                 :     @see error
      39                 : */
      40                 : enum class cond
      41                 : {
      42                 :     /** End-of-stream condition.
      43                 : 
      44                 :         An `error_code` compares equal to `eof` when the stream
      45                 :         reached its natural end, such as when a peer sends TCP FIN
      46                 :         or a file reaches EOF.
      47                 :     */
      48                 :     eof = 1,
      49                 : 
      50                 :     /** Operation cancelled condition.
      51                 : 
      52                 :         An `error_code` compares equal to `canceled` when the
      53                 :         operation's stop token was activated, the I/O object's
      54                 :         `cancel()` was called, or a platform cancellation error
      55                 :         occurred.
      56                 :     */
      57                 :     canceled = 2,
      58                 : 
      59                 :     /** Stream truncated condition.
      60                 : 
      61                 :         An `error_code` compares equal to `stream_truncated` when
      62                 :         a TLS peer closed the connection without sending a proper
      63                 :         shutdown alert.
      64                 :     */
      65                 :     stream_truncated = 3,
      66                 : 
      67                 :     /** Item not found condition.
      68                 : 
      69                 :         An `error_code` compares equal to `not_found` when a
      70                 :         lookup operation failed to find the requested item.
      71                 :     */
      72                 :     not_found = 4
      73                 : };
      74                 : 
      75                 : } // capy
      76                 : } // boost
      77                 : 
      78                 : namespace std {
      79                 : template<>
      80                 : struct is_error_condition_enum<
      81                 :     ::boost::capy::cond>
      82                 :     : std::true_type {};
      83                 : } // std
      84                 : 
      85                 : namespace boost {
      86                 : namespace capy {
      87                 : 
      88                 : namespace detail {
      89                 : 
      90                 : struct BOOST_CAPY_SYMBOL_VISIBLE
      91                 :     cond_cat_type
      92                 :     : std::error_category
      93                 : {
      94                 :     BOOST_CAPY_DECL const char* name(
      95                 :         ) const noexcept override;
      96                 :     BOOST_CAPY_DECL std::string message(
      97                 :         int) const override;
      98                 :     BOOST_CAPY_DECL bool equivalent(
      99                 :         std::error_code const& ec,
     100                 :         int condition) const noexcept override;
     101                 :     constexpr cond_cat_type() noexcept = default;
     102                 : };
     103                 : 
     104                 : BOOST_CAPY_DECL extern cond_cat_type cond_cat;
     105                 : 
     106                 : } // detail
     107                 : 
     108                 : /// Create an error_condition from a cond value.
     109                 : inline
     110                 : std::error_condition
     111 HIT        1395 : make_error_condition(
     112                 :     cond ev) noexcept
     113                 : {
     114            1395 :     return std::error_condition{
     115                 :         static_cast<std::underlying_type<
     116                 :             cond>::type>(ev),
     117            1395 :         detail::cond_cat};
     118                 : }
     119                 : 
     120                 : } // capy
     121                 : } // boost
     122                 : 
     123                 : #endif