simple_enum

expected_ec and make_unexpected_ec

Overview

• expected_ec is a template alias simplifying usage of std::expected with std::error_code for error handling.
• make_unexpected_ec is a utility function creating an unexpected object initialized with a std::error_code generated from an enumeration representing error conditions.

Usage

Ensure inclusion .

#include <simple_enum/generic_error_category.hpp>

expected_ec Type Alias

template<typename T>
using expected_ec = std::expected<T, std::error_code>;

• Usage: Represents a type that may contain a value of type T or an error of type std::error_code.

unexpected_ec Type Alias

using unexpected_ec = std::unexpected<std::error_code>;

• Usage: Simplifies the declaration of an unexpected type carrying a std::error_code.

make_unexpected_ec Function

template<concepts::error_enum ErrorEnum>
[[nodiscard]] auto make_unexpected_ec(ErrorEnum e) -> unexpected_ec;

• Usage: Creates an unexpected_ec object from an enumeration value e representing an error. This leverages make_error_code to convert enumeration to std::error_code.

Example Usage

enum class error_code { none, error1, error2, error3 };

// Using expected_ec and make_unexpected_ec for error handling
auto func() -> expected_ec<int> {
    if(/* error condition */) {
        return make_unexpected_ec(error_code::error1);
    }
    return 42; // Success path returns a value
}

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