#ifndef LLVM_ADT_ITERATOR_H
#define LLVM_ADT_ITERATOR_H
+#include <cstddef>
#include <iterator>
namespace llvm {
/// terms of addition of one. These aren't equivalent for all iterator
/// categories, and respecting that adds a lot of complexity for little gain.
template <typename DerivedT, typename IteratorCategoryT, typename T,
- typename DifferenceTypeT, typename PointerT = T *,
+ typename DifferenceTypeT = std::ptrdiff_t, typename PointerT = T *,
typename ReferenceT = T &>
-struct iterator_facade_base
- : std::iterator<IteratorCategoryT, T, DifferenceTypeT, PointerT,
- ReferenceT> {
+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;
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 {
+ 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);
}
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);
}
};
/// This class can be used through CRTP to adapt one iterator into another.
/// Typically this is done through providing in the derived class a custom \c
/// operator* implementation. Other methods can be overridden as well.
-template <typename DerivedT, typename WrappedIteratorT, typename T,
- typename PointerT = T *, typename ReferenceT = T &,
- // Don't provide these, they are mostly to act as aliases below.
- typename WrappedTraitsT = std::iterator_traits<WrappedIteratorT>>
+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 &,
+ // Don't provide these, they are mostly to act as aliases below.
+ typename WrappedTraitsT = std::iterator_traits<WrappedIteratorT>>
class iterator_adaptor_base
- : public iterator_facade_base<
- DerivedT, typename WrappedTraitsT::iterator_category, T,
- typename WrappedTraitsT::difference_type, PointerT, ReferenceT> {
+ : 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() {}
+ iterator_adaptor_base() = default;
template <typename U>
explicit iterator_adaptor_base(
int>::type = 0)
: I(std::forward<U &&>(u)) {}
+ const WrappedIteratorT &wrapped() const { return I; }
+
public:
- typedef typename WrappedTraitsT::difference_type difference_type;
+ 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 iterator_adaptor_base::iterator_facade_base::operator-;
- difference_type operator-(const DerivedT &RHS) const { return I - RHS.I; }
+ 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;
+ }
// We have to explicitly provide ++ and -- rather than letting the facade
// forward to += because WrappedIteratorT might not support +=.
- using iterator_adaptor_base::iterator_facade_base::operator++;
+ using BaseT::operator++;
DerivedT &operator++() {
++I;
return *static_cast<DerivedT *>(this);
}
- using iterator_adaptor_base::iterator_facade_base::operator--;
+ 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 { 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; }
};
/// \code
/// typedef pointee_iterator<SmallVectorImpl<T *>::iterator> iterator;
/// \endcode
-template <
- typename WrappedIteratorT,
- typename T = typename std::remove_pointer<
- typename std::iterator_traits<WrappedIteratorT>::value_type>::type>
+template <typename WrappedIteratorT,
+ typename T = typename std::remove_reference<
+ decltype(**std::declval<WrappedIteratorT>())>::type>
struct pointee_iterator
- : iterator_adaptor_base<pointee_iterator<WrappedIteratorT>,
- WrappedIteratorT, T> {
- 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)) {}