On 03/09/2012 03:24 PM, Jacob Carlborg wrote:
On 2012-03-09 15:13, Timon Gehr wrote:
On 03/09/2012 01:20 PM, Jacob Carlborg wrote:
On 2012-03-09 12:12, Jonathan M Davis wrote:
On Friday, March 09, 2012 11:03:38 Regan Heath wrote:
On Fri, 09 Mar 2012 08:20:33 -0000, Chris Pons<cmp...@gmail.com>
wrote:
Any idea why, system("PAUSE") does work?
As Jonathan says, assert throws AssertError... which means, if you
wanted
to you could catch it, for example...
module asserting;
import std.stdio;
import core.exception;
debug
{
import std.c.windows.windows;
extern (C) int kbhit();
}
void main()
{
try
{
assert(false, "testing assert");
}
catch(AssertError e)
{
debug
{
writefln("Assertion failed: %s", e);
writefln("Press any key to exit...");
while(!kbhit())
Sleep(1);
}
throw e;
}
}
So, for debug builds your exe will output the assertion manually, and
wait
for a key press. Then re-throw the assertion (resulting in the d
runtime
outputting the assertion again). In release, no pause.
Note: kbhit and Sleep are windows specific (sleep would be the unix
equivalent, not sure on one for kbhit).
Bet advised that catching anything not derived from Exception is
generally a
_bad_ idea (most of which are derived from Error), and AssertError is
_not_
derived from Exception but rather Error. AssertErrors are not
guaranteed to
invoke finally blocks, scope statements, or destructors. Your program
is in an
invalid state when you catch an Error. So, while it may work in this
particular case, it is _not_ something that you should be doing in
general. By
far the worst thing to do would be to catch an Error and then continue
executing. Errors are _supposed_ to kill your program.
- Jonathan M Davis
Then I would say it's bad design to have "assert" throw an AssertError.
Whatever "assert" throws needs to be catchable, this is essential for
writing unit test frameworks. It needs to be possible to write a unit
test framework that catches all AssertErrors and prints a nice report at
the end (or similar).
This is a special case. Jonathan was specifically referring to the
general case.
Then way is it an error?
So that it does not get caught by catch(Exception){}.
I still want it to call finally blocks, scope
statements, and destructors.
I have never actually observed that those are not run for assertion
failures.
