ErrorException thrown when errno is modified ?

[chmike via Digitalmars-d-learn]

Hello,

I'm planning to call some posix functions core.sys.posix that may 
set the errno value in case of error. e.g. read() or write().

Checking the std.exception documentation I see that 
ErrnoException may be thrown when errors setting errno may occur. 
Does this affect the posix calls ?

 From what I saw in the code, it doesn't seam the case. Just 
making sure I'm correct.