RE: [boost] Boost.Assert

From: Chris Little (cslittle_at_[hidden])
Date: 2001-11-12 10:49:52

Peter,

I like the ability to map BOOST_ASSERT into our own error reporting system.

A few comments.

Since assert is only used if BOOST_ASSERT isn't defined, shouldn't the
#include be moved inside the #ifndef BOOST_ASSERT?

Why do we need BOOST_DEBUG instead of just using NDEBUG?  Are you assuming
that people might want use BOOST_ASSERTS in release builds?  Also
BOOST_DEBUG doesn't do anything if BOOST_ASSERT is defined.
 
Another possible variant of BOOST_ASSERT is to have a macro that supplies a
message that is display instead of the expression.  It would look like:

BOOST_ASSERT_MSG( IsOpen(), "The caller should open the file." ) ;

We've found it helpful to sometimes give an explanation for the assert
instead of just the expression.

Chris

> ----------
> From: 	Peter Dimov
> Reply To: 	boost_at_[hidden]
> Sent: 	Monday, November 12, 2001 8:19 AM
> To: 	Boost List
> Subject: 	[boost] Boost.Assert
> 
> See the code at the end for my proposed implementation of BOOST_ASSERT.
> 
> Design goals:
> 
> * Simple;
> * Off by default;
> * User customizable.
> 
> Modes of operation include:
> 
> 1. off; when BOOST_DEBUG is not defined.
> 2. simply use assert(); with -DBOOST_DEBUG and -DBOOST_ASSERT=assert.
> 3. invoke user error handler (boost_error), then assert();
> with -DBOOST_DEBUG.
> 3a. log error and throw.
> 3b. log error and continue.
> 3c. log error and assert().
> 3d. log error and terminate (whole process or current thread only.)
> 3e. perform cleanup and assert().
> 
> etc.
> 
> Comments?
> 
> --
> Peter Dimov
> Multi Media Ltd.
> 
> #define BOOST_DEBUG
> 
> // boost/assert.hpp
> 
> #ifdef BOOST_DEBUG
> #include <assert.h>
> #endif
> 
> #ifndef BOOST_ASSERT
> 
> #ifdef BOOST_DEBUG
> 
> bool boost_error(char const * expr, char const * file, long line);
> 
> #ifndef BOOST_ERROR
> #define BOOST_ERROR(expr) (expr || !boost_error(#expr, __FILE__,
> __LINE__))
> #endif
> 
> #define BOOST_ASSERT(expr) assert(BOOST_ERROR(expr))
> 
> #else
> 
> #define BOOST_ASSERT ((void)0)
> 
> #endif
> 
> #endif
> 
> //
> 
> // user error handler
> 
> #include <cstdio>
> 
> bool boost_error(char const * expr, char const * file, long line)
> {
>  std::printf("boost_error(%s, %s, %ld)\n", expr, file, line);
>  return true;
> }
> 
> //
> 
> // boost or user code
> 
> int main()
> {
>  BOOST_ASSERT(0 == 1);
> }
> 
> 
> 
> 
> Info: http://www.boost.org  Unsubscribe:
> <mailto:boost-unsubscribe_at_[hidden]> 
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
> 
>