expected.hpp File Reference

Detailed Description

For holding a value or an error.

Definition in file expected.hpp.

Go to the source code of this file.

#include <concepts>
#include <stdexcept>
#include <string>
#include <utility>
#include <variant>
#include <userver/compiler/impl/lifetime.hpp>
#include <userver/utils/assert.hpp>

This graph shows which files directly or indirectly include this file:

Classes
class	utils::bad_expected_access
class	utils::unexpected< E >
class	utils::expected< S, E >
	For holding a value or an error. More...
class	utils::expected< void, E >

Namespaces
namespace	utils
	General-purpose utilities used across userver libraries.

Functions
template<class E>
	utils::unexpected (E) -> unexpected< E >
template<class S, class E> requires std::equality_comparable<S> && std::equality_comparable<E>
bool	utils::operator== (const expected< S, E > &lhs, const expected< S, E > &rhs)
	Compares two utils::expected: equal either if both hold equal values, or if both hold equal errors.
template<class S, class E, class T> requires (!std::same_as<T, expected<S, E>>) && std::equality_comparable_with<S, T>
bool	utils::operator== (const expected< S, E > &lhs, const T &rhs)
	Compares utils::expected with a value: equal if lhs holds a value equal to rhs.
template<class S, class E, class G> requires std::equality_comparable_with<E, G>
bool	utils::operator== (const expected< S, E > &lhs, const unexpected< G > &rhs)
	Compares utils::expected with utils::unexpected: equal if lhs holds an error equal to rhs.error().
template<class E> requires std::equality_comparable<E>
bool	utils::operator== (const expected< void, E > &lhs, const expected< void, E > &rhs)
	Compares two utils::expected<void, E>: equal either if both hold a value, or if both hold equal errors.
template<class E, class G> requires std::equality_comparable_with<E, G>
bool	utils::operator== (const expected< void, E > &lhs, const unexpected< G > &rhs)
	Compares utils::expected<void, E> with utils::unexpected: equal if lhs holds an error equal to rhs.error().