Nullable<T> Record

A generic record that wraps a value of type T, adding the ability to represent a null (missing) state.

Remarks

Nullable<T> provides a way to distinguish between a value that has been set and one that is absent. It supports implicit conversions to and from T, comparison operators, and can be set to null by assigning the global SNull variable. Accessing the Value property when the nullable is null raises an ENullConvertException.

Syntax

Unit: Bcl.Types.Nullable

Nullable<T> = record;

Constructors

Name	Description
Create	Creates a new Nullable<T> instance that holds the specified value.

Operators

Name	Description
Equality	Adapts the = operator so it returns true when both instances have the same values.
Inequality	Adapts the <> operator so it returns true when both instances have different values.
GreaterThan	Adapts the > operator so it returns true when the first parameter is bigger than the second.
GreaterThanOrEqual	Adapts the >= operator so it returns true when the first parameter is bigger than or equal to the second.
LessThan	Adapts the < operator so it returns true when the first parameter is smaller than the second.
LessThanOrEqual	Adapts the <= operator so it returns true when the first parameter is smaller than or equal to the second.

Properties

Name	Description
HasValue	Indicates whether the nullable contains a value.
IsNull	Indicates whether the nullable is null (has no value).
Value	Gets or sets the stored value.
ValueOrDefault	Gets the stored value, or the default value of T if the nullable is null.
Empty	Returns a null Nullable<T> instance with no value assigned.