libs/static_assert/example/static_assert_example_2.cpp
// (C) Copyright John Maddock 2000.
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See http://www.boost.org for most recent version including documentation.
#include <boost/static_assert.hpp>
#include <boost/type_traits.hpp>
#include <iterator>
#include <list>
#include <deque>
template <class RandomAccessIterator >
RandomAccessIterator foo(RandomAccessIterator from, RandomAccessIterator /*to*/)
{
// this template can only be used with
// random access iterators...
typedef typename std::iterator_traits< RandomAccessIterator >::iterator_category cat;
BOOST_STATIC_ASSERT((boost::is_convertible<cat, const std::random_access_iterator_tag&>::value));
//
// detail goes here...
return from;
}
int main()
{
std::deque<int> d;
std::list<int> l;
foo(d.begin(), d.end()); // OK
//foo(l.begin(), l.end()); // error
return 0;
}