Instigate Open Source Documentation

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src/stl/_find_if.hpp

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#ifndef _INSTIGATE_STL_INTERNAL_HEADER_IN_ALGORITHM
#error This is an internal header file used to implement Instigate STL.\
        It should never be included directly by a program.
#endif

#ifndef INSTIGATE_STL_FIND_IF_HPP
#define INSTIGATE_STL_FIND_IF_HPP

// Headers from this project
#include "concept.hpp"
#include "_basis.hpp"

// Headers from other project

// Headers from standard library

// Forward declaration
namespace instigate {   
namespace stl { 
        namespace implementation { 
                template <typename I, typename P>
                I find_if_aux(I b, I e, P p,                                
                                instigate::stl::random_access_iterator::tag);
                template <typename I, typename P>
                I find_if_aux(I b, I e, P p, instigate::stl::
                                                single_pass_iterator::tag);
        }
        template <typename I, typename P>
        I find_if(I b, I e, P p);
}
}

template <typename I, typename P>
inline I instigate::stl::find_if(I b, I e, P p)
{
        CHECK(instigate::stl::single_pass_iterator::requirements<I>);
        CHECK(instigate::stl::readable_iterator::requirements<I>);
        CHECK(instigate::stl::unary_predicate::requirements<P>);
        typedef typename instigate::stl::single_pass_iterator::interface<I>::
                iterator_category category;
        return instigate::stl::implementation::find_if_aux(b, e, p, category());
}                                       

template <typename I, typename P>
inline I instigate::stl::implementation::find_if_aux(I b, I e, P p, 
                instigate::stl::random_access_iterator::tag) 
{
        typename instigate::stl::random_access_iterator::interface<I>::
                difference_type t = instigate::stl::distance(b, e) >> 2; 
        for (; 0 < t;) {
                assign(t, t - 1);
                if (invoke_predicate(p, const_dereference(b))) {
                        return b;
                }
                increment(b);
                if (invoke_predicate(p, const_dereference(b))) {
                        return b;
                }
                increment(b);
                if (invoke_predicate(p, const_dereference(b))) {
                        return b;
                }
                increment(b);
                if (invoke_predicate(p, const_dereference(b))) {
                        return b;
                }
                increment(b);
        }
        switch (instigate::stl::distance(b, e)) {
                case 3:
                        if (invoke_predicate(p, const_dereference(b))) {
                                return b;
                        }
                        increment(b);
                case 2:
                        if (invoke_predicate(p, const_dereference(b))) {
                                return b;
                        }
                        increment(b);
                case 1:
                        if (invoke_predicate(p, const_dereference(b))) {
                                return b;
                        }
                        increment(b);
                case 0:
                default:
                        return e;        
        }
}

template <typename I, typename P>
inline I instigate::stl::implementation::find_if_aux(I b, I e, P p, 
                        instigate::stl::single_pass_iterator::tag)
{
        while (!equal(b, e) && !invoke_predicate(p, const_dereference(b)))
        {
                increment(b);
        }
        return b;
}               

// vim:et:tabstop=8:shiftwidth=8:cindent:fo=croq:textwidth=80:

#endif // INSTIGATE_STL_FIND_IF_HPP

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