Function overloading in PowerShell

1) Build a class...

class c1 { 
    [int]f1( [string]$x ){ return 1 } 
    [int]f1( [int ]$x ){ return 2 }
    }

1+) Use STATIC METHODS if you prefer to call them without instantiation...

class c1 { 
    static [int] f1( [string]$x ){ return 1 } 
    static [int] f1( [int]$x ){ return 2 } 
    }

2) Call the methods in class or object... overload works OK

$o1 = [c1]::new()
o1.f1( "abc" ) ~> returns 1
o1.f1( 123 )   ~> returns 2

-OR-

[c1]::f1( "abc" ) ~> returns 1
[c1]::f1( 123 )   ~> returns 2

3) If (like me)
you want to have "Overloaded Functions" placed in a libraries...
so your users can use them transparently...
from code or from Interactive Command Line (REPL)...

the closest I could came to
"Overloading functions in Powershell"
was something like this:

function Alert-String() { [c1]::f1( "abc" ) }
function Alert-Strings(){ [c1]::f1( 123 ) }
function Alert-Stringn(){ [c1]::f1( 123 ) }

Maybe in PS-Core v8??? ;-)

Hope it helps...

If you use PSObject instead of Object to define your parameter type, it should work. For example, The function Get-Control, know's how to overload based on type string or template and can be called using the positional value:

    Get-Control "A-Name-Of-A-Control"
    Get-Control $template

To make the overload work, use PSObject as follows:

Function Get-Control {
    Param(
        [Parameter(Mandatory=$False,ParameterSetName="ByTemplate",Position=0)]
        [PSObject]
        $Template,

        [Parameter(Mandatory=$False,ParameterSetName="ByName",Position=0)]        
        [String]
        $Name,

        [Parameter(Mandatory=$False)] 
        [Switch]
        $List
      ) 
   ... # remaining code removed for brevity