[llvm] r291625 - Add better documentation for iterator facade subclasses.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Tue Jan 10 18:34:41 2017
New Revision: 291625

URL: http://llvm.org/viewvc/llvm-project?rev=291625&view=rev
Log:
Add better documentation for iterator facade subclasses.

Modified:
    llvm/trunk/include/llvm/ADT/iterator.h

Modified: llvm/trunk/include/llvm/ADT/iterator.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/iterator.h?rev=291625&r1=291624&r2=291625&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/iterator.h (original)
+++ llvm/trunk/include/llvm/ADT/iterator.h Tue Jan 10 18:34:41 2017
@@ -33,6 +33,32 @@ namespace llvm {
 /// Another abstraction that this doesn't provide is implementing increment in
 /// terms of addition of one. These aren't equivalent for all iterator
 /// categories, and respecting that adds a lot of complexity for little gain.
+///
+/// Classes wishing to use `iterator_facade_base` should implement the following
+/// methods:
+///
+/// Forward Iterators:
+///   (All of the following methods)
+///   - DerivedT &operator=(const DerivedT &R);
+///   - bool operator==(const DerivedT &R) const;
+///   - const T &operator*() const;
+///   - T &operator*();
+///   - DerivedT &operator++();
+///
+/// Bidirectional Iterators:
+///   (All methods of forward iterators, plus the following)
+///   - DerivedT &operator--();
+///
+/// Random-access Iterators:
+///   (All methods of bidirectional iterators excluding the following)
+///   - DerivedT &operator++();
+///   - DerivedT &operator--();
+///   (and plus the following)
+///   - bool operator<(const DerivedT &RHS) const;
+///   - DifferenceTypeT operator-(const DerivedT &R) const;
+///   - DerivedT &operator+=(DifferenceTypeT N);
+///   - DerivedT &operator-=(DifferenceTypeT N);
+///
 template <typename DerivedT, typename IteratorCategoryT, typename T,
           typename DifferenceTypeT = std::ptrdiff_t, typename PointerT = T *,
           typename ReferenceT = T &>