Summary of the new feature/enhancement

It should be possible to use Out-String in a manner that doesn't append a trailing newline, which is what it currently does and has always done.

Note that -NoNewLine is not a solution, because it suppresses all newlines, so that two or more output lines are then simply directly concatenated (like -join ''; e.g. 1, 2 | Out-String -NoNewLine yields 12).

Here's a demonstration of the problem:

# CURRENT behavior:
PS> ('foo' | Out-String) -replace '\r?\n', '<newline>'
foo<newline>   #  A newline was appended.

I see two options:

• (a) Consider a breaking change - assuming it is justified to consider it a Bucket 3: Unlikely Grey Area change - and make Out-String never append a trailing newline.

• (b) Introduce a new switch, -NoTrailingNewLine (related: Add a -NoLastNewline switch parameter to Write-Host, Set-Content, Add-Content, Out-File, Out-String #5108)