fml::StatusOr< T > Class Template Reference

#include <status_or.h>

Public Member Functions
	StatusOr (const T &value)
	StatusOr (T &&value)
	StatusOr (const Status &status)
	StatusOr (const StatusOr &)=default
	StatusOr (StatusOr &&)=default
StatusOr &	operator= (const StatusOr &)=default
StatusOr &	operator= (StatusOr &&)=default
StatusOr &	operator= (const T &value)
StatusOr &	operator= (const T &&value)
StatusOr &	operator= (const Status &value)
const Status &	status () const
bool	ok () const
const T &	value () const
T &	value ()

Detailed Description

template<typename T>
class fml::StatusOr< T >

Represents a union type of an object of type T and an fml::Status.

This is often used as a replacement for C++ exceptions where a function that could fail may return an error or a result. These are typically used for errors that are meant to be recovered from. If there is no recovery available FML_CHECK is more appropriate.

Example: StatusOr<int> div(int n, int d) { if (d == 0) { return Status(StatusCode::kFailedPrecondition, "div by zero"); } return n / d; }

Definition at line 32 of file status_or.h.

Constructor & Destructor Documentation

StatusOr() [1/5]

template<typename T >

fml::StatusOr< T >::StatusOr ( const T &  value )

inline

Definition at line 36 of file status_or.h.

: status_(), value_(value) {}

StatusOr() [2/5]

template<typename T >

fml::StatusOr< T >::StatusOr ( T &&  value )

inline

Definition at line 40 of file status_or.h.

: status_(), value_(std::move(value)) {}

StatusOr() [3/5]

template<typename T >

fml::StatusOr< T >::StatusOr ( const Status &  status )

inline

Definition at line 44 of file status_or.h.

                                 : status_(status), value_() {
    // It's not valid to construct a StatusOr with an OK status and no value.
    FML_CHECK(!status_.ok());
  }

StatusOr() [4/5]

template<typename T >

fml::StatusOr< T >::StatusOr ( const StatusOr< T > &  )

default

StatusOr() [5/5]

template<typename T >

fml::StatusOr< T >::StatusOr ( StatusOr< T > &&  )

default

Member Function Documentation

ok()

template<typename T >

bool fml::StatusOr< T >::ok ( ) const

inline

Definition at line 75 of file status_or.h.

{ return status_.ok(); }

operator=() [1/5]

template<typename T >

StatusOr & fml::StatusOr< T >::operator= ( const Status &  value )

inline

Definition at line 67 of file status_or.h.

                                           {
    status_ = value;
    value_ = std::nullopt;
    return *this;
  }

operator=() [2/5]

template<typename T >

StatusOr & fml::StatusOr< T >::operator= ( const StatusOr< T > &  )

default

operator=() [3/5]

template<typename T >

StatusOr & fml::StatusOr< T >::operator= ( const T &&  value )

inline

Definition at line 61 of file status_or.h.

                                       {
    status_ = Status();
    value_ = std::move(value);
    return *this;
  }

operator=() [4/5]

template<typename T >

StatusOr & fml::StatusOr< T >::operator= ( const T &  value )

inline

Definition at line 55 of file status_or.h.

                                      {
    status_ = Status();
    value_ = value;
    return *this;
  }

operator=() [5/5]

template<typename T >

StatusOr & fml::StatusOr< T >::operator= ( StatusOr< T > &&  )

default

status()

template<typename T >

const Status & fml::StatusOr< T >::status ( ) const

inline

Definition at line 73 of file status_or.h.

{ return status_; }

value() [1/2]

template<typename T >

T & fml::StatusOr< T >::value ( )

inline

Definition at line 86 of file status_or.h.

             {
    if (value_.has_value()) {
      FML_DCHECK(status_.ok());
      return value_.value();
    }
    FML_LOG(FATAL) << "StatusOr::value() called on error Status";
    FML_UNREACHABLE();
  }

value() [2/2]

template<typename T >

const T & fml::StatusOr< T >::value ( ) const

inline

Definition at line 77 of file status_or.h.

                         {
    if (value_.has_value()) {
      FML_DCHECK(status_.ok());
      return value_.value();
    }
    FML_LOG(FATAL) << "StatusOr::value() called on error Status";
    FML_UNREACHABLE();
  }

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The documentation for this class was generated from the following file:

• fml/status_or.h