Exercise 4-3

Weed out compile-time inefficiencies. More...

Files
file	exercise-4-3.hpp
	Solution to Exercise 4-3.

Namespaces
namespace	test_4_3
	Tests functionality from Exercise 4-3.
namespace	exercise_4_3
	Encapsulate solution for Exercise 4-3.

Detailed Description

Weed out compile-time inefficiencies.

4-3. Eliminate the unnecessary instantiations in the following code snippets:

1:
template <typename N, typename Predicate>
struct next_if
    : mpl::if_<
        typename mpl::apply<Predicate,N>::type,
        typename mpl::next<N>::type,
        N
    > { };

2:
template <typename N1, typename N2>
struct formula
    : mpl::if_<
        mpl::not_equal_to<N1,N2>,
        typename mpl::if_<
            mpl::greater<N1,N2>,
            typename mpl::minus<N1,N2>::type,
            N1
        >::type,
        typename mpl::plus<
            N1,
            typename mpl::multiplies< N1, mpl::int_<2> >::type
        >::type
    >::type
{ };