```
@Documented
@Target(TYPE)
public static @interface Value.Immutable
```
Instruct processor to generate immutable implementation of abstract value type. Classes, Interface and Annotation types are supported including top level and non-private static inner types.
Annotation has attributes to configure generation of immutable implementation classes, which are usually configured per-type: should the builder (builder()) be generated or instances interned (intern()). You can use Value.Style or custom style annotation to tune naming conventions and other settings of code-generation, along with default value for per-type attributes (Value.Style.defaults())
Generated accessor methods have annotation copied from original accessor method. However org.immutables.* and java.lang.* are not copied. Be warned that such immutable object may contain attributes with types that are not guaranteed to be immutable, thus not every object will be recursively immutable. While this may be useful in some cases, one should generally avoid creating immutable object with attribute values that could be mutated.

See Also:

Value.Style, Value.Include

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`boolean`	`builder`	If `builder=false`, disables generation of `builder()`.
`boolean`	`copy`	If `copy=false` then generation of copying methods will be disabled.
`boolean`	`intern`	If `intern=true` then instances will be strong interned on construction.
`boolean`	`lazyhash`	If `lazyhash=true` then internal `hashCode` will be computed (and cached) on first `hashCode()` method call.
`boolean`	`prehash`	If `prehash=true` then `hashCode` will be precomputed during construction.
`boolean`	`singleton`	If `singleton=true`, generates internal singleton object constructed without any specified parameters.

- Element Detail
  - singleton
```
boolean singleton
```
    If singleton=true, generates internal singleton object constructed without any specified parameters. Default is false. To access singleton instance use .of() static accessor method.
    This requires that all attributes have default value (including collections which can be left empty). If some required attributes exist it will result in compilation error. Note that in case object does not have attributes, singleton instance will be generated automatically.
    Note that singleton=true does not imply that only one instance of given abstract type. But it does mean that only one "default" instance of the immutable implementation type exist.
    
    Returns:
    
    if generate singleton default instance
    
    Default:
    
    false
- - intern
```
boolean intern
```
    If intern=true then instances will be strong interned on construction. Default is false.
    
    Returns:
    
    if generate strongly interned instances
    
    Default:
    
    false
- - copy
```
boolean copy
```
    If copy=false then generation of copying methods will be disabled. This applies to static "copyOf" methods as well as modify-by-copy "withAttributeName" methods which return modified copy using structural sharing where possible. Default value is true, i.e generate copy methods.
    
    Returns:
    
    if generate copy methods
    
    Default:
    
    true
- - prehash
```
boolean prehash
```
    If prehash=true then hashCode will be precomputed during construction. This could speed up map/set lookups for objects with lots of attributes and nested objects. In general, use this when hashCode computation is expensive and will be used a lot. Note that if Value.Style.privateNoargConstructor() == true this option will be ignored. For lazy (deferred) hashCode computation use lazyhash()
    
    Returns:
    
    if generate hash code precomputing
    
    Default:
    
    false
- - lazyhash
```
boolean lazyhash
```
    If lazyhash=true then internal hashCode will be computed (and cached) on first hashCode() method call. For eager hashCode computation (in constructor) use prehash().
    
    Returns:
    
    to lazily compute the hashCode
    
    Default:
    
    false
- - builder
```
boolean builder
```
    If builder=false, disables generation of builder(). Default is true.
    
    Returns:
    
    if generate builder
    
    Default:
    
    true

Annotation Type Value.Immutable

Optional Element Summary

Element Detail

singleton

intern

copy

prehash

lazyhash

builder