Struct Optional
Optional type. Also known as a Maybe or Option type in some languages.
struct Optional(T)
;
This can either contain a value or be none. If the value is a refernce type then
null is considered none.
It also has range like behavior. So this acts as a range that contains 1 element or is empty.
And all operations that can be performed on a T can also be performed on an Optional!T. The behavior of applying an operation on a no-value or null pointer is well defined and safe.
Constructors
| Name | Description |
|---|---|
this
(value)
|
Constructs an Optional!T value by assigning T |
Methods
| Name | Description |
|---|---|
opAssign
()
|
Assigns a value to the optional or sets it to none.
|
opBinary
(rhs)
|
If the optional is some value it returns an optional of some value op rhs
|
opBinaryRight
(lhs)
|
If the optional is some value it returns an optional of some lhs op value
|
opCall
(args)
|
If there's a value that's callable it will be called else it's a noop |
opDollar
()
|
Provides indexing into arrays |
opEquals
()
|
Compare two optionals or an optional with some value |
opIndex
(index)
|
Provides indexing into arrays |
opOpAssign
(rhs)
|
If the optional is some value, op assigns rhs to it |
opSlice
(begin, end)
|
Provides indexing into arrays |
opUnary
()
|
Applies unary operator to internal value of optional. |
toString
()
|
Converts value to string |