#ifndef LLVM_ADT_ITERATOR_H
#define LLVM_ADT_ITERATOR_H
#include <cstddef>
#include <iterator>
namespace llvm {
template <typename DerivedT, typename IteratorCategoryT, typename T,
typename DifferenceTypeT = std::ptrdiff_t, typename PointerT = T *,
typename ReferenceT = T &>
class iterator_facade_base
: public std::iterator<IteratorCategoryT, T, DifferenceTypeT, PointerT,
ReferenceT> {
protected:
enum {
IsRandomAccess =
std::is_base_of<std::random_access_iterator_tag, IteratorCategoryT>::value,
IsBidirectional =
std::is_base_of<std::bidirectional_iterator_tag, IteratorCategoryT>::value,
};
public:
DerivedT operator+(DifferenceTypeT n) const {
static_assert(
IsRandomAccess,
"The '+' operator is only defined for random access iterators.");
DerivedT tmp = *static_cast<const DerivedT *>(this);
tmp += n;
return tmp;
}
friend DerivedT operator+(DifferenceTypeT n, const DerivedT &i) {
static_assert(
IsRandomAccess,
"The '+' operator is only defined for random access iterators.");
return i + n;
}
DerivedT operator-(DifferenceTypeT n) const {
static_assert(
IsRandomAccess,
"The '-' operator is only defined for random access iterators.");
DerivedT tmp = *static_cast<const DerivedT *>(this);
tmp -= n;
return tmp;
}
DerivedT &operator++() {
return static_cast<DerivedT *>(this)->operator+=(1);
}
DerivedT operator++(int) {
DerivedT tmp = *static_cast<DerivedT *>(this);
++*static_cast<DerivedT *>(this);
return tmp;
}
DerivedT &operator--() {
static_assert(
IsBidirectional,
"The decrement operator is only defined for bidirectional iterators.");
return static_cast<DerivedT *>(this)->operator-=(1);
}
DerivedT operator--(int) {
static_assert(
IsBidirectional,
"The decrement operator is only defined for bidirectional iterators.");
DerivedT tmp = *static_cast<DerivedT *>(this);
--*static_cast<DerivedT *>(this);
return tmp;
}
bool operator!=(const DerivedT &RHS) const {
return !static_cast<const DerivedT *>(this)->operator==(RHS);
}
bool operator>(const DerivedT &RHS) const {
static_assert(
IsRandomAccess,
"Relational operators are only defined for random access iterators.");
return !static_cast<const DerivedT *>(this)->operator<(RHS) &&
!static_cast<const DerivedT *>(this)->operator==(RHS);
}
bool operator<=(const DerivedT &RHS) const {
static_assert(
IsRandomAccess,
"Relational operators are only defined for random access iterators.");
return !static_cast<const DerivedT *>(this)->operator>(RHS);
}
bool operator>=(const DerivedT &RHS) const {
static_assert(
IsRandomAccess,
"Relational operators are only defined for random access iterators.");
return !static_cast<const DerivedT *>(this)->operator<(RHS);
}
PointerT operator->() const {
return &static_cast<const DerivedT *>(this)->operator*();
}
ReferenceT operator[](DifferenceTypeT n) const {
static_assert(IsRandomAccess,
"Subscripting is only defined for random access iterators.");
return *static_cast<const DerivedT *>(this)->operator+(n);
}
};
template <
typename DerivedT, typename WrappedIteratorT,
typename IteratorCategoryT =
typename std::iterator_traits<WrappedIteratorT>::iterator_category,
typename T = typename std::iterator_traits<WrappedIteratorT>::value_type,
typename DifferenceTypeT =
typename std::iterator_traits<WrappedIteratorT>::difference_type,
typename PointerT = T *, typename ReferenceT = T &,
typename WrappedTraitsT = std::iterator_traits<WrappedIteratorT>>
class iterator_adaptor_base
: public iterator_facade_base<DerivedT, IteratorCategoryT, T,
DifferenceTypeT, PointerT, ReferenceT> {
typedef typename iterator_adaptor_base::iterator_facade_base BaseT;
protected:
WrappedIteratorT I;
iterator_adaptor_base() = default;
template <typename U>
explicit iterator_adaptor_base(
U &&u,
typename std::enable_if<
!std::is_base_of<typename std::remove_cv<
typename std::remove_reference<U>::type>::type,
DerivedT>::value,
int>::type = 0)
: I(std::forward<U &&>(u)) {}
const WrappedIteratorT &wrapped() const { return I; }
public:
typedef DifferenceTypeT difference_type;
DerivedT &operator+=(difference_type n) {
static_assert(
BaseT::IsRandomAccess,
"The '+=' operator is only defined for random access iterators.");
I += n;
return *static_cast<DerivedT *>(this);
}
DerivedT &operator-=(difference_type n) {
static_assert(
BaseT::IsRandomAccess,
"The '-=' operator is only defined for random access iterators.");
I -= n;
return *static_cast<DerivedT *>(this);
}
using BaseT::operator-;
difference_type operator-(const DerivedT &RHS) const {
static_assert(
BaseT::IsRandomAccess,
"The '-' operator is only defined for random access iterators.");
return I - RHS.I;
}
using BaseT::operator++;
DerivedT &operator++() {
++I;
return *static_cast<DerivedT *>(this);
}
using BaseT::operator--;
DerivedT &operator--() {
static_assert(
BaseT::IsBidirectional,
"The decrement operator is only defined for bidirectional iterators.");
--I;
return *static_cast<DerivedT *>(this);
}
bool operator==(const DerivedT &RHS) const { return I == RHS.I; }
bool operator<(const DerivedT &RHS) const {
static_assert(
BaseT::IsRandomAccess,
"Relational operators are only defined for random access iterators.");
return I < RHS.I;
}
ReferenceT operator*() const { return *I; }
};
template <typename WrappedIteratorT,
typename T = typename std::remove_reference<
decltype(**std::declval<WrappedIteratorT>())>::type>
struct pointee_iterator
: iterator_adaptor_base<
pointee_iterator<WrappedIteratorT>, WrappedIteratorT,
typename std::iterator_traits<WrappedIteratorT>::iterator_category,
T> {
pointee_iterator() = default;
template <typename U>
pointee_iterator(U &&u)
: pointee_iterator::iterator_adaptor_base(std::forward<U &&>(u)) {}
T &operator*() const { return **this->I; }
};
}
#endif