folly::result

Synopsis

Declared in <folly/result/result.h>

template<typename T = void>
class [[nodiscard]] result final
    : public /* implementation-defined */

The default specialization is non-void (but result<> defaults to void).

Name	Description
`/* implementation-defined */`

Name	Description
`promise_type`	* Protocols *
`value_type`

Name	Description
`result` [constructor]	Constructors
`~result` [destructor]	Destroys the stored value when in the value state.
`operator=`	Assignment operators
`copy` [deprecated]	`result<T>` is copyable iff `T` is copyable.
`error_or_stopped`	Error-or-stopped access should be used SPARINGLY!
`get_exception`
`get_mutable_exception`
`get_pointer`	`get_pointer` overloads
`has_stopped`
`has_value`	* Accessors for `T` `void` and non-`void` ***
`non_value`
`value_or_throw`	`value_or_throw` overloads

Name	Description
`value_` [variant member]	Stored value or reference wrapper; valid only in the value state.

Name
`has_value_sigil_t`
`storage_type`

Name
`operator=` [deleted]
`throw_if_no_value`

Name
`rewrapping_result_convert`

Name
`eos_`

Name	Description
`result<void>`	Specialization for `T = void` aka `result<>`. Uses no `value_` storage.

Name	Description
`result<T&>`	Deduction guide: `std::reference_wrapper<T>` yields `result<T&>`.
`result<T&&>`	Deduction guide: `rvalue_reference_wrapper<T>` yields `result<T&&>`.

Name	Description
`folly::operator==`	Compares two `result` values for equality.
`folly::result`	A value, an error (`std::exception_ptr`), or a "stopped"/cancellation state.

Name	Description
`epitaph`	Annotates the error state of a `result<T>` with an epitaph message.
`or_unwind_epitaph`	or_unwind_epitaph
`result_to_try`	Converts a `result<T>` to a `Try<T>`.
`stack_epitaph`	Annotates the error state of a `result<T>` with a stack-trace epitaph.
`try_to_result`	If `t` is empty, defaults to returning a `UsingUninitializedTry` result. Pick your own default via `empty_try_with{ { return result<T>{...}; }`.
`try_to_result`	Converts a `Try<T>` to a `result<T>`, treating empty as an error.