Re: [boost] [parameter] - catching accidental duplicate parameters at compile time

On 11/3/05, David Abrahams <dave@boost-consulting.com> wrote:

Something like:

static char (& has_key(K const&) )[2];

BOOST_MPL_ASSERT_MSG( sizeof(Next::has_key(make<K>())) == 1 , duplicate_keyword, (K) );

If you could submit a patch to the current CVS along with an expected-compilation-failure test case, I'd be happy to apply it.

Excellent, thanks. One question about the above code: is make<> already declared somewhere? In the meantime I've added this as a member of arg_list: template <class T> static const T &make(); Or how about passing has_key a pointer, as NULL pointers are easy to make? Apologies for my ignorance about these details. --Daniel.