Boost logo

Boost :

From: Douglas Gregor (doug.gregor_at_[hidden])
Date: 2005-02-23 19:17:03

On Feb 23, 2005, at 10:34 AM, christopher diggins wrote:
> Christopher Diggins
> Object Oriented Template Library (OOTL)
> ----- Original Message ----- From: "Douglas Gregor"
> <doug.gregor_at_[hidden]>
> To: <boost_at_[hidden]>
> Sent: Wednesday, February 23, 2005 8:27 AM
> Subject: Re: [boost] STL containers with contracts, any interest?
> Hi Doug,
> 1) The proposed PwC approach would provide consistent behaviour across
> STL implementations.

Isn't that more a property of the adaptor approach than PwC? You can
pass any container to the adaptor, regardless of the underlying
library, and it will perform the checks when it interfaces with that

At least two of the debug modes I'd mentioned (GCC libstdc++ and
STLport) use wrappers/adaptors to implement debug-mode semantics, and I
suspect the others do as well. Nothing actually ties the debug modes to
a particular library except a few #defines and/or some namespace

> 2) The contract verification classes would make it much easier to
> write new classes which model STL containers and verify that they
> exhibit correct behaviour.


> Also consider the following code:
> template<Vector_T>
> void MyAlgorithm(Vector_T& x) {
> // do stuff ...
> }
> If we get a hand-rolled vector type (instead of an STL vector) we have
> no way of knowing whether or not it conforms to the expected contract
> even if we can check it conforms to the correct concept. Using
> contract classes we could instead write (using an imaginary
> vector_contract_concept):
> template<Vector_T>
> void MyAlgorithm(Vector_T& x) {
> #ifdef DEBUG
> BOOST_STATIC_ASSERT(vector_contract_concept<Vector_T>::satisfied)
> #endif
> // do stuff
> }

I don't understand this part... it looks like a concept check (i.e.,
syntax), but above it sounds like you're saying that this verifies the
contract (i.e., semantics). How can we check the semantics with a
static assert?


Boost list run by bdawes at, gregod at, cpdaniel at, john at