Bug 183890 [DataBinding] Default converter for numbers to numbers
We don't currently default converters for converting between numbers (e.g. int to double, long to int, etc.).
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/UpdateValueStrategy.java
private HashMap validators = new HashMap();
		/**
		 * Adds the system-provided validators to the current validator
		 * registry. This is done automatically for the validator registry
		 * singleton.
		 */
		private ValidatorRegistry() {
			
			associate(Integer.class, Integer.TYPE,
					new ObjectToPrimitiveValidator(Integer.TYPE));
			associate(Byte.class, Byte.TYPE, new ObjectToPrimitiveValidator(
					Byte.TYPE));
			associate(Short.class, Short.TYPE, new ObjectToPrimitiveValidator(
					Short.TYPE));
			associate(Long.class, Long.TYPE, new ObjectToPrimitiveValidator(
					Long.TYPE));
			associate(Float.class, Float.TYPE, new ObjectToPrimitiveValidator(
					Float.TYPE));
			associate(Double.class, Double.TYPE,
					new ObjectToPrimitiveValidator(Double.TYPE));
			associate(Boolean.class, Boolean.TYPE,
					new ObjectToPrimitiveValidator(Boolean.TYPE));