function Test-SelectFirst {
    param(
        [Parameter(Mandatory,ParameterSetName='Array')]
        [psobject[]]$InputCollection,

        [Parameter(Mandatory,ParameterSetName='ScriptBlock')]
        [scriptblock]$Pipeline
    )

    switch($PSCmdlet.ParameterSetName){
        'Array'{
            $(Measure-Command {
                $f,$null = $InputCollection
            }),
            $(Measure-Command {
                $f = $InputCollection |Select -First 1
            }),
            $(Measure-Command {
                $f = $InputCollection[0]
            }) |% ToString G
        }
        'ScriptBlock'{
            $(Measure-Command {
                $f,$null = &$Pipeline
            }),
            $(Measure-Command {
                $f = &$Pipeline |Select -First 1
            }),
            $(Measure-Command {
                $f = @(&$Pipeline)[0]
            }) |% ToString G
        }
    }
}

Write-Host 'Test results for 1..100: ' -f Green
Test-SelectFirst -InputCollection (1..100)
Write-Host '-----------------------------'

Write-Host 'Test results for 1..10000: ' -f Green
Test-SelectFirst -InputCollection (1..10000)
Write-Host '-----------------------------'

Write-Host 'Test results for 1..1000000: ' -f Green
Test-SelectFirst -InputCollection (1..1000000)
Write-Host '-----------------------------'

Write-Host 'Test results for slow pipeline' -f Green
Test-SelectFirst -Pipeline {1..10 |%{Get-Random; Start-Sleep -Milliseconds 150}}
Write-Host '-----------------------------'