Re: Expression cannot be evaluated

From:

"Alexander Nickolov" <agnickolov@mvps.org>

Newsgroups:

microsoft.public.vc.language

Date:

Tue, 21 Aug 2007 12:56:40 -0700

Message-ID:

<OuMCd1C5HHA.6024@TK2MSFTNGP05.phx.gbl>

Still, these are rather esoteric... The only other common source
of that display in the debugger is dereferencing an invalid pointer
(NULL for example).

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://vcfaq.mvps.org
=====================================

"Ben Voigt [C++ MVP]" <rbv@nospam.nospam> wrote in message
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"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp> wrote in message
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"Jack" <jl@knight.com> wrote in message
news:%23IGo$574HHA.5360@TK2MSFTNGP03.phx.gbl...

Hello,
I've this message in the debug pane.
CXX0030: Expression cannot be evaluated...
Does it have something to do with COM?
Thanks
Jack

It usually means you are asking the debugger to display a local variable
outside the scope of that variable.

Or your expression refers to a user-overloaded operator.
Or your expression refers to a static member of a type without fully
qualifying it.
Or your expression contains a macro.
Or ...

Not all code can be directly cut+pasted from a source file into the Watch
window, because the debugger doesn't have all the stateful knowledge the
compiler does, such as namespace search scopes, macros, and the like.