Ошибка компилятора шаблона C ++

Я обновляю старый код Visual Studio C ++ и не могу определить, что не так с этим кодом.

TLineApproximator<T>::PointContainer::iterator TDPHull<typename T>::DP(typename PointContainer::iterator it, typename PointContainer::iterator jt)
{
static double ld, rd, len_sq;
static SHomog l;
register SPoint *le;
register SPoint *re;

SPoint* i=&(*it);
SPoint* j=&(*jt);

SPoint::CrossProduct(*i, *j, l);
len_sq = l.x * l.x + l.y * l.y;

if (j - i < 8)
{       /* chain small */
rd  = 0.0;
for (le = i + 1; le < j; le++)
{
ld = SPoint::DotProduct(*le, l);
if (ld < 0) ld = - ld;
if (ld > rd)
{
rd = ld;
re = le;
}
}
if (rd * rd > GetTol() * len_sq)
{
OutputVertex(DP(i, re));
return(DP(re, j));
}
else
return(j);
}
else
{               /* chain large */
int sbase, sbrk, mid, lo, m1, brk, m2, hi;
double d1, d2;
if ((m_phLeft.GetTop() - m_phLeft.GetBot()) > 8)
{
/* left hull large */
lo = m_phLeft.GetBot();
hi = m_phLeft.GetTop() - 1;
sbase = m_phLeft.SlopeSign(hi, lo, l);
do
{
brk = (lo + hi) / 2;
if (sbase == (sbrk = m_phLeft.SlopeSign(brk, brk+1, l)))
if (sbase == (m_phLeft.SlopeSign(lo, brk+1, l)))
lo = brk + 1;
else
hi = brk;
}
while (sbase == sbrk && lo < hi);

m1 = brk;
while (lo < m1)
{
mid = (lo + m1) / 2;
if (sbase == (m_phLeft.SlopeSign(mid, mid+1, l)))
lo = mid + 1;
else
m1 = mid;
}

m2 = brk;
while (m2 < hi)
{
mid = (m2 + hi) / 2;
if (sbase == (m_phLeft.SlopeSign(mid, mid+1, l)))
hi = mid;
else
m2 = mid + 1;
};if ((d1 = SPoint::DotProduct(*m_phLeft.GetpElt(lo), l)) < 0) d1 = - d1;
if ((d2 = SPoint::DotProduct(*m_phLeft.GetpElt(m2), l)) < 0) d2 = - d2;
ld = (d1 > d2 ? (le = m_phLeft.GetpElt(lo), d1) : (le = m_phLeft.GetpElt(m2), d2));
}
else
{           /* Few SPoints in left hull */
ld = 0.0;
for (mid = m_phLeft.GetBot(); mid < m_phLeft.GetTop(); mid++)
{
if ((d1 = SPoint::DotProduct(*m_phLeft.GetpElt(mid), l)) < 0) d1 = - d1;
if (d1 > ld)
{
ld = d1;
le = m_phLeft.GetpElt(mid);
}
}
}

if ((m_phRight.GetTop() - m_phRight.GetBot()) > 8)
{           /* right hull large */
lo = m_phRight.GetBot(); hi = m_phRight.GetTop() - 1;
sbase = m_phRight.SlopeSign(hi, lo, l);
do
{
brk = (lo + hi) / 2;
if (sbase == (sbrk = m_phRight.SlopeSign(brk, brk+1, l)))
if (sbase == (m_phRight.SlopeSign(lo, brk+1, l)))
lo = brk + 1;
else
hi = brk;
}
while (sbase == sbrk && lo < hi);

m1 = brk;
while (lo < m1)
{
mid = (lo + m1) / 2;
if (sbase == (m_phRight.SlopeSign(mid, mid+1, l)))
lo = mid + 1;
else
m1 = mid;
}

m2 = brk;
while (m2 < hi)
{
mid = (m2 + hi) / 2;
if (sbase == (m_phRight.SlopeSign(mid, mid+1, l)))
hi = mid;
else
m2 = mid + 1;
};

if ((d1 = SPoint::DotProduct(*m_phRight.GetpElt(lo), l)) < 0) d1 = - d1;
if ((d2 = SPoint::DotProduct(*m_phRight.GetpElt(m2), l)) < 0) d2 = - d2;
rd = (d1 > d2 ? (re = m_phRight.GetpElt(lo), d1) : (re = m_phRight.GetpElt(m2), d2));
}
else
{           /* Few SPoints in righthull */
rd = 0.0;
for (mid = m_phRight.GetBot(); mid < m_phRight.GetTop(); mid++)
{
if ((d1 = SPoint::DotProduct(*m_phRight.GetpElt(mid), l)) < 0) d1 = - d1;
if (d1 > rd)
{
rd = d1;
re = m_phRight.GetpElt(mid);
}
}
}
}if (ld > rd)
if (ld * ld > GetTol() * len_sq)
{               /* split left */
register int tmpo;

while ((m_phLeft.GetHp() >= 0)
&& ( (tmpo = m_phLeft.GetpOp()[m_phLeft.GetHp()] ),
((re = m_phLeft.GetpHelt(m_phLeft.GetHp())) != le) || (tmpo != TPathHull<T>::StackPushOp)))
{
m_phLeft.DownHp();
switch (tmpo)
{
case TPathHull<T>::StackPushOp:
m_phLeft.DownTop();
m_phLeft.UpBot();
break;
case TPathHull<T>::StackTopOp:
m_phLeft.UpTop();
m_phLeft.SetTopElt(re);
break;
case TPathHull<T>::StackBotOp:
m_phLeft.DownBot();
m_phLeft.SetBotElt(re);
break;
}
}

Build(i, le);
OutputVertex(DP(i, le));
Build(le, j);
return DP(le, j);
}
else
return(j);
else                /* extreme on right */
if (rd * rd > GetTol() * len_sq)
{               /* split right or both */
if (m_pPHtag == re)
Build(i, re);
else
{           /* split right */
register int tmpo;

while ((m_phRight.GetHp() >= 0)
&& ((tmpo = m_phRight.GetpOp()[m_phRight.GetHp()]),
((le = m_phRight.GetpHelt(m_phRight.GetHp())) != re) || (tmpo != TPathHull<T>::StackPushOp)))
{
m_phRight.DownHp();
switch (tmpo)
{
case TPathHull<T>::StackPushOp:
m_phRight.DownTop();
m_phRight.UpBot();
break;
case TPathHull<T>::StackTopOp:
m_phRight.UpTop();
m_phRight.SetTopElt(le);
break;
case TPathHull<T>::StackBotOp:
m_phRight.DownBot();
m_phRight.SetBotElt(le);
break;
}
}
}
OutputVertex(DP(i, re));
Build(re, j);
return(DP(re, j));
}
else
return(j);
}

Ошибка:

 dphull.h(155) : error C2664: 'hull::TDPHull<T>::DP' : cannot convert
parameter 1 from 'hull::TLineApproximator<T>::SPoint *' to
'std::_Vector_iterator<_Ty,_Alloc>'
with
[
T=double
]
and
[
T=double
]
and
[
_Ty=hull::TLineApproximator<double>::SPoint,
_Alloc=std::allocator<hull::TLineApproximator<double>::SPoint>
]
No constructor could take the source type, or constructor overload resolution was ambiguous dphull.h(128) : while compiling
class template member function 'std::_Vector_iterator<_Ty,_Alloc>
hull::TDPHull<T>::DP(std::_Vector_iterator<_Ty,_Alloc>,std::_Vector_iterator<_Ty,_Alloc>)'
with
[
_Ty=hull::TLineApproximator<double>::SPoint,
_Alloc=std::allocator<hull::TLineApproximator<double>::SPoint>,
T=double
]
d:\src\inc`lude\`pglline2dlod.h(127) : see reference to class template instantiation 'hull::TDPHull<T>' being compiled
with
[
T=double
]

SPoint* i=&(*it);

Функция DP def

template <class T>
typename TLineApproximator<T>::PointContainer::iterator TDPHull<typename T>::DP(typename PointContainer::iterator it, typename PointContainer::iterator jt)