class ErrorOr

Declaration

template <class T>
class ErrorOr { /* full declaration omitted */ };

Description

Represents either an error or a value T. ErrorOr <T > is a pointer-like class that represents the result of an operation. The result is either an error, or a value of type T. This is designed to emulate the usage of returning a pointer where nullptr indicates failure. However instead of just knowing that the operation failed, we also have an error_code and optional user data that describes why it failed. It is used like the following. Implicit conversion to bool returns true if there is a usable value. The unary * and -> operators provide pointer like access to the value. Accessing the value when there is an error has undefined behavior. When T is a reference type the behavior is slightly different. The reference is held in a std::reference_wrapper <std ::remove_reference <T >::type>, and there is special handling to make operator -> work as if T was not a reference. T cannot be a rvalue reference.

Declared at: llvm/include/llvm/Support/ErrorOr.h:56

Templates

T

Method Overview

• public ErrorOr<T>(std::error_code EC)
• public ErrorOr<T>(const ErrorOr<T> & Other)
• public ErrorOr<T>(ErrorOr<T> && Other)
• public template <class E> ErrorOr<T>(E ErrorCode, typename std::enable_if<std::is_error_code_enum<E>::value || std::is_error_condition_enum<E>::value, void *>::type = nullptr)
• public template <class OtherT> ErrorOr<T>(OtherT && Val, typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * = nullptr)
• public template <class OtherT> ErrorOr<T>(const ErrorOr<OtherT> & Other, typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * = nullptr)
• public template <class OtherT> ErrorOr<T>(const ErrorOr<OtherT> & Other, typename std::enable_if<!std::is_convertible<OtherT, const T &>::value>::type * = nullptr)
• public template <class OtherT> ErrorOr<T>(ErrorOr<OtherT> && Other, typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * = nullptr)
• public template <class OtherT> ErrorOr<T>(ErrorOr<OtherT> && Other, typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * = nullptr)
• public llvm::ErrorOr::reference get()
• public llvm::ErrorOr::const_reference get() const
• public std::error_code getError() const
• public bool operator bool() const
• public ~ErrorOr<T>()

Methods

¶ErrorOr<T>(std::error_code EC)

Declared at: llvm/include/llvm/Support/ErrorOr.h:82

Parameters

std::error_code EC

¶ErrorOr<T>(const ErrorOr<T>& Other)

Declared at: llvm/include/llvm/Support/ErrorOr.h:94

Parameters

const ErrorOr<T>& Other

¶ErrorOr<T>(ErrorOr<T>&& Other)

Declared at: llvm/include/llvm/Support/ErrorOr.h:114

Parameters

ErrorOr<T>&& Other

¶template <class E>
ErrorOr<T>(
    E ErrorCode,
    typename std::enable_if<
        std::is_error_code_enum<E>::value ||
            std::is_error_condition_enum<
                E>::value,
        void*>::type = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:74

Templates

E

Parameters

E ErrorCode

typename std::enable_if< std::is_error_code_enum<E>::value || std::is_error_condition_enum<E>::value, void*>::type = nullptr

¶template <class OtherT>
ErrorOr<T>(
    OtherT&& Val,
    typename std::enable_if<
        std::is_convertible<OtherT, T>::value>::
        type* = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:87

Templates

OtherT

Parameters

OtherT&& Val

typename std::enable_if< std::is_convertible<OtherT, T>::value>::type* = nullptr

¶template <class OtherT>
ErrorOr<T>(
    const ErrorOr<OtherT>& Other,
    typename std::enable_if<
        std::is_convertible<OtherT, T>::value>::
        type* = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:99

Templates

OtherT

Parameters

const ErrorOr<OtherT>& Other

typename std::enable_if< std::is_convertible<OtherT, T>::value>::type* = nullptr

¶template <class OtherT>
ErrorOr<T>(
    const ErrorOr<OtherT>& Other,
    typename std::enable_if<!std::is_convertible<
        OtherT,
        const T&>::value>::type* = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:107

Templates

OtherT

Parameters

const ErrorOr<OtherT>& Other

typename std::enable_if< !std::is_convertible<OtherT, const T&>::value>::type* = nullptr

¶template <class OtherT>
ErrorOr<T>(
    ErrorOr<OtherT>&& Other,
    typename std::enable_if<
        std::is_convertible<OtherT, T>::value>::
        type* = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:119

Templates

OtherT

Parameters

ErrorOr<OtherT>&& Other

typename std::enable_if< std::is_convertible<OtherT, T>::value>::type* = nullptr

¶template <class OtherT>
ErrorOr<T>(
    ErrorOr<OtherT>&& Other,
    typename std::enable_if<
        !std::is_convertible<OtherT, T>::value>::
        type* = nullptr)

Declared at: llvm/include/llvm/Support/ErrorOr.h:129

Templates

OtherT

Parameters

ErrorOr<OtherT>&& Other

typename std::enable_if< !std::is_convertible<OtherT, T>::value>::type* = nullptr

¶llvm::ErrorOr::reference get()

Declared at: llvm/include/llvm/Support/ErrorOr.h:156

¶llvm::ErrorOr::const_reference get() const

Declared at: llvm/include/llvm/Support/ErrorOr.h:157

¶std::error_code getError() const

Declared at: llvm/include/llvm/Support/ErrorOr.h:159

¶bool operator bool() const

Description

Return false if there is an error.

Declared at: llvm/include/llvm/Support/ErrorOr.h:152

¶~ErrorOr<T>()

Declared at: llvm/include/llvm/Support/ErrorOr.h:146