static I sized_impl(I const begin_, S end, D const d_, D count,
V const &val, C &pred, P &proj)
{
D d = d_; // always the distance from begin to end
auto begin = uncounted(begin_);
while(true)
{
// Find begin element in sequence 1 that matches val, with a mininum of loop checks
while(true)
{
if(d < count) // return the end if we've run out of room
return ranges::next(recounted(begin_, std::move(begin), d_ - d), std::move(end));
if(pred(proj(*begin), val))
break;
++begin;
--d;
}
// *begin matches val, now match elements after here
auto m = begin;
D c = 0;
while(true)
{
if(++c == count) // If pattern exhausted, begin is the answer (works for 1 element pattern)
return recounted(begin_, std::move(begin), d_ - d);
++m; // No need to check, we know we have room to match successfully
if(!pred(proj(*m), val)) // if there is a mismatch, restart with a new begin
{
begin = next(std::move(m));
d -= (c+1);
break;
} // else there is a match, check next elements
}
}
}
static I1 sized_impl(I1 const begin1_, S1 end1, D1 const d1_, I2 begin2, S2 end2, D2 d2,
C &pred, P1 &proj1, P2 &proj2)
{
D1 d1 = d1_;
auto begin1 = uncounted(begin1_);
while(true)
{
// Find begin element in sequence 1 that matches *begin2, with a mininum of loop checks
while(true)
{
if(d1 < d2) // return the end if we've run out of room
return ranges::next(recounted(begin1_, std::move(begin1), d1_ - d1), std::move(end1));
if(pred(proj1(*begin1), proj2(*begin2)))
break;
++begin1;
--d1;
}
// *begin1 matches *begin2, now match elements after here
auto m1 = begin1;
I2 m2 = begin2;
while(true)
{
if(++m2 == end2) // If pattern exhausted, begin1 is the answer (works for 1 element pattern)
return recounted(begin1_, std::move(begin1), d1_ - d1);
++m1; // No need to check, we know we have room to match successfully
if(!pred(proj1(*m1), proj2(*m2))) // if there is a mismatch, restart with a new begin1
{
++begin1;
--d1;
break;
} // else there is a match, check next elements
}
}
}
static I sized_impl(I const begin_, I end, D d, D count, V const &val,
C &pred, P &proj)
{
if(d < count)
return end;
auto begin = uncounted(begin_);
auto const s = uncounted(end - (count - 1)); // Start of pattern match can't go beyond here
while(true)
{
// Find first element in sequence that matches val, with a mininum of loop checks
while(true)
{
if(begin >= s) // return the end if we've run out of room
return end;
if(pred(proj(*begin), val))
break;
++begin;
}
// *begin matches val, now match elements after here
auto m = begin;
D c = 0;
while(true)
{
if(++c == count) // If pattern exhausted, begin is the answer (works for 1 element pattern)
return recounted(begin_, std::move(begin));
++m; // No need to check, we know we have room to match successfully
if(!pred(proj(*m), val)) // if there is a mismatch, restart with a new begin
{
begin = next(std::move(m));
break;
} // else there is a match, check next elements
}
}
}
O operator()(O begin, iterator_difference_t<O> n, V const & val) const
{
RANGES_ASSERT(n >= 0);
auto norig = n;
auto b = uncounted(begin);
for(; n != 0; ++b, --n)
*b = val;
return recounted(begin, b, norig);
}
std::pair<O, F> operator()(O begin, iterator_difference_t<O> n, F fun) const
{
RANGES_ASSERT(n >= 0);
auto norig = n;
auto b = uncounted(begin);
for(; 0 != n; ++b, --n)
*b = fun();
return {recounted(begin, b, norig), fun};
}
I operator()(I begin, difference_type_t<I> n, F fun, P proj = P{}) const
{
RANGES_EXPECT(0 <= n);
auto norig = n;
auto b = uncounted(begin);
for(; 0 < n; ++b, --n)
invoke(fun, invoke(proj, *b));
return recounted(begin, b, norig);
}
tagged_pair<tag::out(O), tag::fun(F)>
operator()(O begin, difference_type_t<O> n, F fun) const
{
RANGES_EXPECT(n >= 0);
auto norig = n;
auto b = uncounted(begin);
for(; 0 != n; ++b, --n)
*b = invoke(fun);
return {recounted(begin, b, norig), detail::move(fun)};
}
std::pair<I, O>
operator()(I begin, iterator_difference_t<I> n, O out) const
{
RANGES_ASSERT(0 <= n);
auto norig = n;
auto b = uncounted(begin);
for(; n != 0; ++b, ++out, --n)
*out = *b;
return {recounted(begin, b, norig), out};
}
std::pair<I, O>
operator()(I begin, iterator_difference_t<I> n, O out, P proj_ = P{}) const
{
RANGES_ASSERT(0 <= n);
auto &&proj = invokable(proj_);
auto norig = n;
auto b = uncounted(begin);
for(; n != 0; ++b, ++out, --n)
*out = proj(*b);
return {recounted(begin, b, norig), out};
}
std::tuple<I0, I1, O>
operator()(I0 begin0, iterator_difference_t<I0> n0,
I1 begin1, iterator_difference_t<I1> n1,
O out, C r = C{}, P0 p0 = P0{}, P1 p1 = P1{}) const
{
using T = std::tuple<I0, I1, O>;
auto &&ir = invokable(r);
auto &&ip0 = invokable(p0);
auto &&ip1 = invokable(p1);
auto n0orig = n0;
auto n1orig = n1;
auto b0 = uncounted(begin0);
auto b1 = uncounted(begin1);
while(true)
{
if(0 == n0)
{
auto res = copy_n(b1, n1, out);
begin0 = recounted(begin0, b0, n0orig);
begin1 = recounted(begin1, res.first, n1orig);
return T{begin0, begin1, res.second};
}
if(0 == n1)
{
auto res = copy_n(b0, n0, out);
begin0 = recounted(begin0, res.first, n0orig);
begin1 = recounted(begin1, b1, n1orig);
return T{begin0, begin1, res.second};
}
if(ir(ip1(*b1), ip0(*b0)))
{
*out = *b1;
++b1; ++out; --n1;
}
else
{
*out = *b0;
++b0; ++out; --n0;
}
}
}
I operator()(I begin, S end, C pred_, P proj_ = P{}) const
{
auto && pred = invokable(pred_);
auto && proj = invokable(proj_);
auto len = distance(begin, end);
while(len != 0)
{
auto const half = len / 2;
auto middle = next(uncounted(begin), half);
if(pred(proj(*middle)))
{
begin = recounted(begin, std::move(++middle), half + 1);
len -= half + 1;
}
else
len = half;
}
return begin;
}