Temporary Types
Creates a temporary copy of a user defined type
Syntax
`
result = Type( initializers, ... )
or
result = Type<typename>( initializers, ... )
`
Parameters
`initializers`
Initial values for the type
`typename`
The name of the `Type` or `Union`
Return Value
A temporary copy of the type.
Description
Used to create a temporary type. If `typename` is not explicitly given, it will be inferred from its usage if possible. Usage of the temporary copy may include assigning it to a variable, passing it as a parameter to a procedure, or returning it as a value from a procedure.
For a type without constructor, the temporary type syntax is allowed if all type data-fields are numeric primitives only and without any default initializers, but the compiler does a direct assignment instead of using a temporary copy if at same time the type is without destructor.
The `Constructor` for the type, if there is one, will be called when the temporary copy is created, and the `Destructor` for the type, if there is one, will be called immediately after its use. But when there is a constructor, the temporary type expression may be simply replaced by `typename( initializers, ... )`.
It can create not only a temporary copy of an user defined type, but also a temporary copy of predefined data-type as a variable-length string or any numeric data-type (all standard data-types excluding fixed-length strings).
It can also be used as an even shorter shortcut than `With` (see below) if you are changing all the records.
Example
`
Type Example
As Integer field1
As Integer field2
End Type
Dim ex As Example
'' Filling the type by setting each field
ex.field1 = 1
ex.field2 = 2
'' Filling the type by setting each field using WITH
With ex
.field1 = 1
.field2 = 2
End With
'' Fill the variable's fields with a temporary type
ex = Type( 1, 2 )
`
`
'' Passing a user-defined types to a procedure using a temporary type
'' where the type can be inferred.
Type S
As Single x, y
End Type
Sub test ( v As S )
Print "S", v.x, v.y
End Sub
test( Type( 1, 2 ) )
`
`
'' Passing a user-defined type to a procedure using temporary types
'' where the type is ambiguous and the name of the type must be specified.
Type S
As Single x, y
End Type
Type T
As Integer x, y
End Type
Union U
As Integer x, y
End Union
'' Overloaded procedure test()
Sub test Overload ( v As S )
Print "S", v.x, v.y
End Sub
Sub test ( v As T )
Print "T", v.x, v.y
End Sub
Sub test ( v As U )
Print "U", v.x, v.y
End Sub
'' Won't work: ambiguous
'' test( type( 1, 2 ) )
'' Specify name of type instead
test( Type<S>( 1, 2 ) )
test( Type<T>( 1, 2 ) )
test( Type<U>( 1 ) )
`
Differences from QB

- New to FreeBASIC

See also

- `Type...End Type`
- `Type (Alias)`