Re: [boost] Review: Test library

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-02-19 09:49:01

At 07:35 PM 2/18/2001 -0600, Ed Brey wrote:

 >I like the idea in your subsequent post of
 >providing non-macro exit_failure and exit_success and then modelling the
 >test-library variants off of those.

I've thought about it a bit more, and think it would be worthwhile.  It 
seems to me that the correct place to put such constants would be in a 
<boost/cstdlib.hpp> header, since they aren't really part of the test 
library.

The contents might be something like this:

//  boost/cstdlib.hpp header

#ifndef BOOST_CSTDLIB_HPP
#define BOOST_CSTDLIB_HPP

#include <cstdlib>

namespace boost
{
   //  The intent is to propose the following for addition to namespace std
   //  in the C++ Standard Library, and to then deprecate EXIT_SUCCESS and
   //  EXIT_FAILURE.  As an implementation detail, this header defines the
   //  new constants in terms of EXIT_SUCCESS and EXIT_FAILURE.  In a new
   //  standard, the constants would be implementation-defined, although it
   //  might be worthwhile to "suggest" (which a standard is allowed to do)
   //  values of 0 and 1 respectively.

   //  Rationale for several failure constants: some environments may wish
   //  to distinguish between different classes of errors.
   //  Rationale for choice of values: programs often use values < 100 for
   //  their own error reporting.  Values > 255 are sometimes reserved for
   //  system detected errors.  200/201 were suggested to minimize 
conflict.

   const int exit_success = EXIT_SUCCESS;  // implementation-defined value
   const int exit_failure = EXIT_FAILURE;  // implementation-defined value
   const int exit_exception_failure = 200;
   const int exit_test_failure = 201;
}

#endif

Comments?

 >Actually, after looking more closely at 18.3/8 in the Standard, it seems
 >pretty clear that the check should be like this (pseudo-code):
 >    if (return_value == 0 || return_value == exit_success)
 >        std::cout << "Successful termination\n";
 >    else if (return_value == exit_failure)
 >        std::cout << "Unsuccessful termination\n";
 >    else
 >        std::cout << "Termination with non-standard return value\n";
 >
 >One could make a pragmatic argument for lumping the last case above in 
with
 >the unsuccessful termination case, but I don't see any reason not to do 
the
 >check for 0 or EXIT_SUCCESS by the book.

I went back and reread 18.3/8 and believe your interpretation is 
correct.  I'll make changes accordingly.

--Beman