ValueRef (Spring Framework 4.3.30.RELEASE API)

All Known Implementing Classes:
ValueRef.NullValueRef, ValueRef.TypedValueHolderValueRef
```
public interface ValueRef
```
Represents a reference to a value. With a reference it is possible to get or set the value. Passing around value references rather than the values themselves can avoid incorrect duplication of operand evaluation. For example in 'list[index++]++' without a value reference for 'list[index++]' it would be necessary to evaluate list[index++] twice (once to get the value, once to determine where the value goes) and that would double increment index.
Since:
3.2
Author:
Andy Clement

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`ValueRef.NullValueRef`	A ValueRef for the null value.
`static class`	`ValueRef.TypedValueHolderValueRef`	A ValueRef holder for a single value, which cannot be set.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`TypedValue`	`getValue()`	Returns the value this ValueRef points to, it should not require expression component re-evaluation.
`boolean`	`isWritable()`	Indicates whether calling setValue(Object) is supported.
`void`	`setValue(Object newValue)`	Sets the value this ValueRef points to, it should not require expression component re-evaluation.

- Method Detail
  - getValue
```
TypedValue getValue()
```
    Returns the value this ValueRef points to, it should not require expression component re-evaluation.
    Returns:
    the value
  - setValue
```
void setValue(Object newValue)
```
    Sets the value this ValueRef points to, it should not require expression component re-evaluation.
    Parameters:
    newValue - the new value
  - isWritable
```
boolean isWritable()
```
    Indicates whether calling setValue(Object) is supported.
    Returns:
    true if setValue() is supported for this value reference.