containers::Result< T, E > Class Template Reference

A sum type representing either a success value or an error. More...

#include <containers.hpp>

Public Member Functions
const E &	error () const
	Unwrap the error.
bool	is_err () const
	Check if this result is an error.
bool	is_ok () const
	Check if this result is a success.
const T &	value () const
	Unwrap the success value.

Static Public Member Functions
static Result	err (E error)
	Create an error result.
static Result	ok (T value)
	Create a success result.

Detailed Description

template<typename T, typename E = std::string>
class containers::Result< T, E >

A sum type representing either a success value or an error.

Inspired by Rust's Result<T, E>. Uses std::variant internally.

Template Parameters

T	The success type.
E	The error type (default: std::string).

Example:

Result<int, std::string> divide(int a, int b) {
    if (b == 0) return Result<int, std::string>::err("division by zero");
    return Result<int, std::string>::ok(a / b);
}

See also

Stack, RingBuffer

Definition at line 220 of file containers.hpp.

Member Function Documentation

err()

template<typename T, typename E = std::string>

static Result containers::Result< T, E >::err ( E error )

inlinestatic

Create an error result.

Parameters

error

The error value.

Returns

A Result containing the error.

Definition at line 234 of file containers.hpp.

{ return Result(ErrTag{}, std::move(error)); }

References error().

error()

template<typename T, typename E = std::string>

const E & containers::Result< T, E >::error ( ) const

inlinenodiscard

Unwrap the error.

Returns

The contained error.

Exceptions

std::bad_variant_access

if this is a success.

Definition at line 256 of file containers.hpp.

{ return std::get<E>(data_); }

Referenced by err().

is_err()

template<typename T, typename E = std::string>

bool containers::Result< T, E >::is_err ( ) const

inlinenodiscard

Check if this result is an error.

Definition at line 242 of file containers.hpp.

{ return !is_ok(); }

References is_ok().

is_ok()

template<typename T, typename E = std::string>

bool containers::Result< T, E >::is_ok ( ) const

inlinenodiscard

Check if this result is a success.

Definition at line 237 of file containers.hpp.

                                     {
        return std::holds_alternative<T>(data_);
    }

Referenced by is_err().

ok()

template<typename T, typename E = std::string>

static Result containers::Result< T, E >::ok ( T value )

inlinestatic

Create a success result.

Parameters

value

The success value.

Returns

A Result containing the value.

Definition at line 227 of file containers.hpp.

{ return Result(std::move(value)); }

References value().

value()

template<typename T, typename E = std::string>

const T & containers::Result< T, E >::value ( ) const

inlinenodiscard

Unwrap the success value.

Returns

The contained value.

Exceptions

std::bad_variant_access

if this is an error.

Definition at line 249 of file containers.hpp.

{ return std::get<T>(data_); }

Referenced by ok().

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

• demo/src/containers.hpp