template <typename V = void, typename E = void>class result
Defined at line 121 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
Represents the result of a task which may have succeeded, failed,
or still be in progress.
Use |fpromise::pending()|, |fpromise::ok
<T
>()|, or |fpromise::error
<T
>| to initialize
the result.
|V| is the type of value produced when the completes successfully.
Defaults to |void|.
|E| is the type of error produced when the completes with an error.
Defaults to |void|.
EXAMPLE:
fpromise::result
<int
, std::string> divide(int dividend, int divisor) {
if (divisor == 0)
return fpromise::error
<std
::string>("divide by zero");
return fpromise::ok(dividend / divisor);
}
int try_divide(int dividend, int divisor) {
auto result = divide(dividend, divisor);
if (result.is_ok()) {
printf("%d / %d = %d\n", dividend, divisor, result.value());
return result.value();
}
printf("%d / %d: ERROR %s\n", dividend, divisor, result.error().c_str());
return -999;
}
EXAMPLE WITH VOID RESULT VALUE AND ERROR:
fpromise::result
<
> open(std::string secret) {
printf("guessing \"%s
"
", secret.c_str());
if (secret == "sesame") {
return fpromise::ok();
puts("yes!");
}
puts("no.");
return fpromise::error();
}
bool guess_combination() {
return open("friend") || open("sesame") || open("I give up");
}
Public Methods
void result<V, E> ()Creates a pending result.
Defined at line 127 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void result<V, E> (pending_result )Defined at line 128 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void result<V, E> (ok_result<V> result)Creates an ok result.
Defined at line 131 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename OtherV, typename = std::enable_if_t<std::is_constructible<V, OtherV>::value>>void result<V, E> (ok_result<OtherV> other)Defined at line 133 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void result<V, E> (error_result<E> result)Creates an error result.
Defined at line 137 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename OtherE, typename = std::enable_if_t<std::is_constructible<E, OtherE>::value>>void result<V, E> (error_result<OtherE> other)Defined at line 139 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void result<V, E> (const result<V, E> & other)Copies another result (if copyable).
Defined at line 143 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void result<V, E> (result<V, E> && other)Moves from another result, leaving the other one in a pending state.
Defined at line 146 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void ~result<V, E> ()Defined at line 148 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
result_state state ()Returns the state of the task's result: pending, ok, or error.
Defined at line 151 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
bool operator bool ()Returns true if the result is not pending.
Defined at line 154 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
bool is_pending ()Returns true if the task is still in progress.
Defined at line 157 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
bool is_ok ()Returns true if the task succeeded.
Defined at line 160 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
bool is_error ()Returns true if the task failed.
Defined at line 163 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = V, typename = std::enable_if_t<!std::is_void<R>::value>>R & value ()Gets the result's value.
Asserts that the result's state is |fpromise::result_state::ok|.
Defined at line 168 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = V, typename = std::enable_if_t<!std::is_void<R>::value>>const R & value ()Defined at line 172 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = V, typename = std::enable_if_t<!std::is_void<R>::value>>R take_value ()Takes the result's value, leaving it in a pending state.
Asserts that the result's state is |fpromise::result_state::ok|.
Defined at line 179 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
ok_result<V> take_ok_result ()Defined at line 184 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = E, typename = std::enable_if_t<!std::is_void<R>::value>>R & error ()Gets a reference to the result's error.
Asserts that the result's state is |fpromise::result_state::error|.
Defined at line 193 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = E, typename = std::enable_if_t<!std::is_void<R>::value>>const R & error ()Defined at line 197 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
template <typename R = E, typename = std::enable_if_t<!std::is_void<R>::value>>R take_error ()Takes the result's error, leaving it in a pending state.
Asserts that the result's state is |fpromise::result_state::error|.
Defined at line 204 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
error_result<E> take_error_result ()Defined at line 209 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
result<V, E> & operator= (const result<V, E> & other)Assigns from another result (if copyable).
Defined at line 216 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
result<V, E> & operator= (result<V, E> && other)Moves from another result, leaving the other one in a pending state.
Defined at line 219 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h
void swap (result<V, E> & other)Swaps results.
Defined at line 226 of file ../../sdk/lib/fit-promise/include/lib/fpromise/result.h