Attribute Reference

[ValueObject]

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Applied to a partial class or partial struct. Triggers generation of all equality members.

[ValueObject]
public partial class OrderId { ... }

[ValueObject]
public partial struct Quantity { ... }

Property: ForceClass (bool, default false)

When your declaration is a struct but you need reference semantics, set ForceClass = true. The generator emits a sealed partial class instead of a readonly partial struct.

// Declared as struct, generated as sealed class
[ValueObject(ForceClass = true)]
public partial struct LegacyId
{
    public int Value { get; }
}

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[EqualityMember]

Applied to a property. Switches the type into opt-in mode: only properties marked [EqualityMember] participate in equality. All other properties are ignored.

Opt-in mode activates the moment any property in the type carries this attribute.

[ValueObject]
public partial class Address
{
    [EqualityMember] public string Street { get; }
    [EqualityMember] public string City { get; }
    [EqualityMember] public string PostalCode { get; }

    // Intentionally excluded from equality
    public string? Alias { get; }
    public DateTime LastUpdated { get; }
}

Two addresses with identical Street/City/PostalCode but different Alias values are equal.

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[IgnoreEqualityMember]

Applied to a property. All public properties with getters participate in equality except those marked with this attribute (opt-out mode).

[ValueObject]
public partial class Product
{
    public string Sku { get; }
    public string Name { get; }

    // Internal tracking — irrelevant to domain equality
    [IgnoreEqualityMember] public string InternalCode { get; }
    [IgnoreEqualityMember] public Guid AuditId { get; }
}

Two products with the same Sku and Name are equal regardless of InternalCode or AuditId.

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Summary table

Attribute	Target	Effect
[ValueObject]	partial class or partial struct	Triggers code generation
[ValueObject(ForceClass = true)]	partial struct	Generates a sealed class instead of readonly struct
[EqualityMember]	Property	Opt-in: only marked props are compared
[IgnoreEqualityMember]	Property	Opt-out: all props except marked ones are compared