Alias

Declares an alternative name for an intrinsic type, user-defined Type, Interface, or another Alias. The alias and the original type are interchangeable — assigning between them is not a type mismatch. Comparable to typedef in C/C++.

Note

The Alias statement is a twinBASIC extension. It has no equivalent in classic VBA, where the only use of the Alias keyword is to name a DLL entry point in a Declare statement.

Syntax:

[ Public | Private ] Alias aliasname As type

Public: optional The alias is exported to the type library of an ActiveX DLL or control, so consumers in other projects see aliasname itself.
Private: optional The alias is visible only within the project. Usages of a Private alias are replaced with the underlying type during compilation, so aliasname never appears in the project’s type library.
aliasname: The name of the alias. Must be a valid twinBASIC identifier.
type: The original type. May be an intrinsic type, a user-defined Type, an Interface, or another Alias.

Alias statements are valid only in .twin source files (not legacy .bas or .cls files), and must appear at file scope — outside of Module and Class blocks, alongside Interface and CoClass declarations.

Example

Aliasing intrinsic types and a user-defined type:

The Type goes inside a Module, where a Type must be; the aliases go outside it, where an Alias must be. Both are in the same .twin file:

Module Geometry
    Public Type POINT
        x As Long
        y As Long
    End Type
End Module

Public Alias POINTAPI As POINT

Public Alias CBoolean As Byte

Public Alias KAFFINITY As LongPtr

A variable declared with the alias and a variable declared with the original type are interchangeable:

Dim p As POINT
Dim q As POINTAPI
p = q   ' OK -- no type mismatch.

Alias

Example

See Also