diff options
author | Alkis Evlogimenos <alkis@evlogimenos.com> | 2004-02-14 01:17:28 +0000 |
---|---|---|
committer | Alkis Evlogimenos <alkis@evlogimenos.com> | 2004-02-14 01:17:28 +0000 |
commit | bc79471be19e412eed4d270908db7ac945be10ca (patch) | |
tree | 0bb7850e774204a8883774021f63d84a635236a8 /include/llvm/ADT/STLExtras.h | |
parent | 036e639623a77232dd8826b0c8e4de301fdbee09 (diff) | |
download | llvm-bc79471be19e412eed4d270908db7ac945be10ca.tar.gz llvm-bc79471be19e412eed4d270908db7ac945be10ca.tar.bz2 llvm-bc79471be19e412eed4d270908db7ac945be10ca.tar.xz |
Add next() and prior() iterator utility functions. Unlike std::advance
they do not modify the passed iterator but return a copy.
next(myIt) returns copy of myIt incremented once
next(myIt, n) returns copy of myIt incremented n times
prior(myIt) returns copy of myIt decremented once
prior(myIt, n) returns copy of myIt decremented n times
While at it remove obsolete implementation of mapped_iterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11429 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/ADT/STLExtras.h')
-rw-r--r-- | include/llvm/ADT/STLExtras.h | 60 |
1 files changed, 37 insertions, 23 deletions
diff --git a/include/llvm/ADT/STLExtras.h b/include/llvm/ADT/STLExtras.h index 5ebceb346a..1a53768317 100644 --- a/include/llvm/ADT/STLExtras.h +++ b/include/llvm/ADT/STLExtras.h @@ -75,7 +75,6 @@ static inline void deleter(T *Ptr) { // // It turns out that this is disturbingly similar to boost::transform_iterator // -#if 1 template <class RootIt, class UnaryFunc> class mapped_iterator { RootIt current; @@ -131,28 +130,6 @@ operator+(typename mapped_iterator<_Iterator, Func>::difference_type N, return mapped_iterator<_Iterator, Func>(X.getCurrent() - N); } -#else - -// This fails to work, because some iterators are not classes, for example -// vector iterators are commonly value_type **'s -template <class RootIt, class UnaryFunc> -class mapped_iterator : public RootIt { - UnaryFunc Fn; -public: - typedef typename UnaryFunc::result_type value_type; - typedef typename UnaryFunc::result_type *pointer; - typedef void reference; // Can't modify value returned by fn - - typedef mapped_iterator<RootIt, UnaryFunc> _Self; - typedef RootIt super; - inline explicit mapped_iterator(const RootIt &I) : super(I) {} - inline mapped_iterator(const super &It) : super(It) {} - - inline value_type operator*() const { // All this work to do - return Fn(super::operator*()); // this little thing - } -}; -#endif // map_iterator - Provide a convenient way to create mapped_iterators, just like // make_pair is useful for creating pairs... @@ -163,6 +140,43 @@ inline mapped_iterator<ItTy, FuncTy> map_iterator(const ItTy &I, FuncTy F) { } +// next/prior - These functions unlike std::advance do not modify the +// passed iterator but return a copy. +// +// next(myIt) returns copy of myIt incremented once +// next(myIt, n) returns copy of myIt incremented n times +// prior(myIt) returns copy of myIt decremented once +// prior(myIt, n) returns copy of myIt decremented n times + +template <typename ItTy, typename Dist> +inline ItTy next(ItTy it, Dist n) +{ + std::advance(it, n); + return it; +} + +template <typename ItTy> +inline ItTy next(ItTy it) +{ + std::advance(it, 1); + return it; +} + +template <typename ItTy, typename Dist> +inline ItTy prior(ItTy it, Dist n) +{ + std::advance(it, -n); + return it; +} + +template <typename ItTy> +inline ItTy prior(ItTy it) +{ + std::advance(it, -1); + return it; +} + + //===----------------------------------------------------------------------===// // Extra additions to <algorithm> //===----------------------------------------------------------------------===// |