Re: [boost] Re: any_function (callback) library

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-04-12 09:19:42

At 07:03 PM 4/11/2001, David Abrahams wrote:

 >... discussion and reference to "Errors and Exception Handling" paper

Dave, if I've followed you correctly, you are arguing that:

* "invariants and postconditions should be asserted"

* precondition assertions are desirable, but not always possible, and thus 
a QOI issue.

* For release builds, you also favor throwing an exception for all three 
cases (with the precondition QOI caveat), but only if both the following 
criteria are true:

    - Do we want stack unwinding here?

    - Can we afford stack unwinding here?

Am I wrong in thinking that the user of a library rather than the 
implementor is often the best person to answer those questions?

If so, what do you think of Bill Kempf's suggestion of a BOOST_ASSERT() 
which asserted in debug mode, and is user configurable in release mode to 
throw or not?

Wouldn't that put error handling on a lot firmer ground that the current 
uncertainty?

(I know that implies debug/throw/nothrow library builds (rather than just 
debug/release) but let's assume we are willing to pay that cost.)

--Beman