[
Note 2: 
When tracing the execution of a program with a debugger, an implementation
returns 
true.An implementation performs an immediate query, as needed,
to determine if the program is traced by a debugger
.On Windows or equivalent
systems, this can be achieved by calling the 
::IsDebuggerPresent() Win32
function
.On POSIX, this can be achieved by checking for a tracer parent process,
with best effort determination that such a tracer parent process is a debugger
. — 
end note]