Class OneOf<T1, T2, T3>

Namespace

REslava.Result.AdvancedPatterns

Assembly

REslava.Result.dll

Represents a value that can be one of three possible types. A type-safe discriminated union for functional programming patterns.

public sealed class OneOf<T1, T2, T3> : OneOfBase<T1, T2, T3>, IOneOf<T1, T2, T3>, IEquatable<OneOf<T1, T2, T3>>

Type Parameters

T1

The first possible type.

T2

The second possible type.

T3

The third possible type.

Inheritance

object

OneOfBase<T1, T2, T3>

OneOf<T1, T2, T3>

Implements

IOneOf<T1, T2, T3>

IEquatable<OneOf<T1, T2, T3>>

Inherited Members

OneOfBase<T1, T2, T3>.IsT1

OneOfBase<T1, T2, T3>.IsT2

OneOfBase<T1, T2, T3>.IsT3

OneOfBase<T1, T2, T3>.AsT1

OneOfBase<T1, T2, T3>.AsT2

OneOfBase<T1, T2, T3>.AsT3

OneOfBase<T1, T2, T3>.Match<TResult>(Func<T1, TResult>, Func<T2, TResult>, Func<T3, TResult>)

OneOfBase<T1, T2, T3>.Switch(Action<T1>, Action<T2>, Action<T3>)

OneOfBase<T1, T2, T3>.ToString()

OneOfBase<T1, T2, T3>.Equals(object)

OneOfBase<T1, T2, T3>.GetHashCode()

object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

OneOfExtensions.ToFourWay<T1, T2, T3, T4>(OneOf<T1, T2, T3>, T4)

OneOfExtensions.ToTwoWay<T1, T2, T3>(OneOf<T1, T2, T3>)

OneOfExtensions.ToTwoWay<T1, T2, T3>(OneOf<T1, T2, T3>, Func<T3, T1>?, Func<T3, T2>?)

ValidationExtensions.EnsureNotNull<TCollection>(TCollection?, string, string?)

Remarks

OneOf<T1, T2, T3> provides a type-safe way to represent a value that can be one of three types. This is useful for scenarios where you need to handle different types of values or states without using null references, exceptions, or complex enums.

Common use cases include: - API responses with three states: Success, ClientError, ServerError - Configuration values: String, Integer, Boolean - Database operations: Created, Updated, Deleted

OneOf<SuccessData, ClientError, ServerError> response = await CallApi();
return response.Match(
    case1: data => ProcessData(data),
    case2: clientError => HandleClientError(clientError),
    case3: serverError => HandleServerError(serverError)
);

Methods

BindT2<TNewT2>(Func<T2, OneOf<T1, TNewT2, T3>>)

Binds the T2 value if present, otherwise propagates other types.

public OneOf<T1, TNewT2, T3> BindT2<TNewT2>(Func<T2, OneOf<T1, TNewT2, T3>> binder)

Parameters

binder Func<T2, OneOf<T1, TNewT2, T3>>

Returns

OneOf<T1, TNewT2, T3>

Type Parameters

TNewT2

Exceptions

ArgumentNullException

Thrown when binder is null.

BindT3<TNewT3>(Func<T3, OneOf<T1, T2, TNewT3>>)

Binds the T3 value if present, otherwise propagates other types.

public OneOf<T1, T2, TNewT3> BindT3<TNewT3>(Func<T3, OneOf<T1, T2, TNewT3>> binder)

Parameters

binder Func<T3, OneOf<T1, T2, TNewT3>>

Returns

OneOf<T1, T2, TNewT3>

Type Parameters

TNewT3

Exceptions

ArgumentNullException

Thrown when binder is null.

Equals(OneOf<T1, T2, T3>?)

Determines equality between two OneOf instances.

public bool Equals(OneOf<T1, T2, T3>? other)

Parameters

other OneOf<T1, T2, T3>

Returns

bool

Equals(object?)

Determines whether the specified object is equal to the current object.

public override bool Equals(object? obj)

Parameters

obj object

The object to compare with the current object.

Returns

bool

true if the specified object is equal to the current object; otherwise, false.

FromT1(T1)

Creates a OneOf containing a T1 value.

public static OneOf<T1, T2, T3> FromT1(T1 value)

Parameters

value T1

Returns

OneOf<T1, T2, T3>

FromT2(T2)

Creates a OneOf containing a T2 value.

public static OneOf<T1, T2, T3> FromT2(T2 value)

Parameters

value T2

Returns

OneOf<T1, T2, T3>

FromT3(T3)

Creates a OneOf containing a T3 value.

public static OneOf<T1, T2, T3> FromT3(T3 value)

Parameters

value T3

Returns

OneOf<T1, T2, T3>

GetHashCode()

Serves as the default hash function.

public override int GetHashCode()

Returns

int

A hash code for the current object.

MapT2<TNewT2>(Func<T2, TNewT2>)

Maps the T2 value if present, otherwise propagates other types.

public OneOf<T1, TNewT2, T3> MapT2<TNewT2>(Func<T2, TNewT2> mapper)

Parameters

mapper Func<T2, TNewT2>

Returns

OneOf<T1, TNewT2, T3>

Type Parameters

TNewT2

Exceptions

ArgumentNullException

Thrown when mapper is null.

MapT3<TNewT3>(Func<T3, TNewT3>)

Maps the T3 value if present, otherwise propagates other types.

public OneOf<T1, T2, TNewT3> MapT3<TNewT3>(Func<T3, TNewT3> mapper)

Parameters

mapper Func<T3, TNewT3>

Returns

OneOf<T1, T2, TNewT3>

Type Parameters

TNewT3

Exceptions

ArgumentNullException

Thrown when mapper is null.

Operators

operator ==(OneOf<T1, T2, T3>?, OneOf<T1, T2, T3>?)

Equality operator for OneOf instances.

public static bool operator ==(OneOf<T1, T2, T3>? left, OneOf<T1, T2, T3>? right)

Parameters

left OneOf<T1, T2, T3>

right OneOf<T1, T2, T3>

Returns

bool

implicit operator OneOf<T1, T2, T3>(T1)

Implicit conversion from T1 to OneOf<T1, T2, T3>.

public static implicit operator OneOf<T1, T2, T3>(T1 value)

Parameters

value T1

Returns

OneOf<T1, T2, T3>

implicit operator OneOf<T1, T2, T3>(T2)

Implicit conversion from T2 to OneOf<T1, T2, T3>.

public static implicit operator OneOf<T1, T2, T3>(T2 value)

Parameters

value T2

Returns

OneOf<T1, T2, T3>

implicit operator OneOf<T1, T2, T3>(T3)

Implicit conversion from T3 to OneOf<T1, T2, T3>.

public static implicit operator OneOf<T1, T2, T3>(T3 value)

Parameters

value T3

Returns

OneOf<T1, T2, T3>

operator !=(OneOf<T1, T2, T3>?, OneOf<T1, T2, T3>?)

Inequality operator for OneOf instances.

public static bool operator !=(OneOf<T1, T2, T3>? left, OneOf<T1, T2, T3>? right)

Parameters

left OneOf<T1, T2, T3>

right OneOf<T1, T2, T3>

Returns

bool