Re: Testing for code that should not compile?

From:

"Victor Bazarov" <v.Abazarov@comAcast.net>

Newsgroups:

comp.lang.c++.moderated

Date:

14 Jul 2006 17:09:02 -0400

Message-ID:

<GdWdnfcOK6txcSvZnZ2dnUVZ_vWdnZ2d@comcast.com>

francis_r wrote:

Writing some test cases today I wondered if it would be possible to
assert that something does not compile.

What for?

For example you want to make sure that a class, say Widget, has no
default constructor. Then you would write:
ASSERT_NO_COMPILE ( Widget(); ) // compile time check

Not sure what it buys you. I've not had to rely on something that
doesn't exist, only on something that does.

Or may at runtime.

At runtime *what*?

I think it's possible to write a Testing Framework
that allows you to pass C++ statements as a string that will be
compiled by a compiler that was fired up by the Testing Framework at
run time.

That would call for some kind of compiler API. It is absolutely
possible. Compilers are programs and can allow hooking into them.

Tester::CheckNoCompile( "Widget();" ); // Tester should report error
if it compiles on Tester's compiler

Has something like this ever been done?

Probably. However, usefulness of it is highly questionable.

Do you think it's an
interesting idea?

Not really. Do you?

V
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