How to invert bool false/true in alias compose?

[Timon Gehr]

On 07.12.19 05:00, Marcone wrote:
> import std;
> 
> alias cmd = compose!(to!bool, wait, spawnShell, to!string);
> 
> void main(){
>      writeln(cmd("where notepad.exe"));
> }
> 
> 
> Result:
> 
> C:\Windows\System32\notepad.exe
> C:\Windows\notepad.exe
> false
> 
> 
> The result show "false" because good spawnshell command return 0 and 0 
> to bool is false. But I want to invert false to true to get true or 
> false if command success.

alias cmd = compose!(not!(to!bool), wait, spawnShell, to!string);