:github_url: https://github.com/nyx-org/gaia


.. _program_listing_file_lib_result.hpp:

Program Listing for File result.hpp
===================================

|exhale_lsh| :ref:`Return to documentation for file <file_lib_result.hpp>` (``lib/result.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /* SPDX-License-Identifier: BSD-2-Clause */
   #pragma once
   #include <frg/variant.hpp>
   #include <lib/log.hpp>
   #ifdef __KERNEL__
   #include <posix/errno.hpp>
   #endif
   #include <utility>
   
   namespace Gaia {
   
   struct Void {};
   
   template <typename T = Void> class Ok {
   public:
     constexpr explicit Ok(T value) : value(std::move(value)) {}
   
     T value;
   };
   
   template <typename T> class Err {
   public:
     constexpr explicit Err(T value) : value(value) {}
     T value;
   };
   
   template <typename T, typename E> class Result {
   public:
     constexpr Result(Ok<T> value) : variant(std::move(value)) {}
     constexpr Result(Err<E> value) : variant(std::move(value)) {}
   
     constexpr bool is_ok() { return variant.template is<Ok<T>>(); }
   
     constexpr bool is_err() { return variant.template is<Err<E>>(); }
   
     constexpr T
     unwrap(const FormatWithLocation &fmt =
                "unwrap failed: cannot unwrap an error type, err: {}") {
       if (is_ok())
         return value().value();
       panic(fmt, error_to_string(error().value()));
     }
   
     constexpr T unwrap_or(T _value) {
       if (is_ok())
         return value().value();
       return _value;
     }
   
     constexpr frg::optional<E> error() {
       if (is_err())
         return variant.template get<Err<E>>().value;
       return frg::null_opt;
     }
   
     constexpr frg::optional<T> value() {
       if (is_ok())
         return std::move(variant.template get<Ok<T>>().value);
       return frg::null_opt;
     }
   
   private:
     frg::variant<Ok<T>, Err<E>> variant;
   };
   
   #define TRY(X)                                                                 \
     ({                                                                           \
       auto __ret = (X);                                                          \
       if (__ret.is_err())                                                        \
         return Err(__ret.error().value());                                       \
       __ret.value().value();                                                     \
     })
   
   } // namespace Gaia