mgl_result_wrapper.h

[詳解]

// SPDX-License-Identifier: Zlib
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
 
#ifndef INCGUARD_MGL_RESULT_WRAPPER_H_1611140530
#define INCGUARD_MGL_RESULT_WRAPPER_H_1611140530
 
#include <type_traits>
 
namespace MGL
{
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
template <typename ErrorType, ErrorType noErrorValue = ErrorType(), ErrorType defaultErrorValue = noErrorValue>
class ResultWrapper
{
public:
    static constexpr ErrorType kNoError = noErrorValue;              
    static constexpr ErrorType kDefaultError = defaultErrorValue;    
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr ResultWrapper(ErrorType error) noexcept
        : _error(error)
    {}
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr ResultWrapper() noexcept
        : _error(defaultErrorValue)
    {}
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr ErrorType GetError() const noexcept
    {
        return _error;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr std::underlying_type_t<ErrorType> GetErrorCode() const noexcept
    {
        return static_cast<std::underlying_type_t<ErrorType>>(_error);
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr void SetError(ErrorType error) noexcept
    {
        _error = error;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr void Success() noexcept
    {
        _error = noErrorValue;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    static constexpr ResultWrapper Succeeded() noexcept
    {
        return ResultWrapper(noErrorValue);
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr ResultWrapper &operator=(const ErrorType &rhs) noexcept
    {
        _error = rhs;
        return *this;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr bool operator==(const ErrorType &rhs) const noexcept
    {
        return _error == rhs;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr bool operator!=(const ErrorType &rhs) const noexcept
    {
        return _error != rhs;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr bool HasError() const noexcept
    {
        return _error != noErrorValue;
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr bool IsSucceeded() const noexcept
    {
        return !HasError();
    }
 
private:
    ErrorType _error;
};
}    // namespace MGL
 
#endif    // INCGUARD_MGL_RESULT_WRAPPER_H_1611140530
 
// vim: et ts=4 sw=4 sts=4