Mention conditional conformance to LazySequenceProtocol in the guides

Author: timvermeulen

Guides/Chain.md

@@ -29,12 +29,12 @@ extension Sequence {
     public func chained<S: Sequence>(with other: S) -> Concatenation<Self, S>
         where Element == S.Element
 }
-
 ```
 
-The resulting `Chain` type is a sequence, with conditional conformance to the
-`Collection`, `BidirectionalCollection`, and `RandomAccessCollection`  when both
-the first and second arguments conform.
+The resulting `Chain` type is a sequence, with conditional conformance to
+`Collection`, `BidirectionalCollection`, and `RandomAccessCollection` when both
+the first and second arguments conform. `Chain` also conforms to
+`LazySequenceProtocol` when the first argument conforms.
 
 ### Naming
 

Guides/Combinations.md

@@ -51,7 +51,8 @@ Since the `Combinations` type needs to store an array of the collection’s
 indices and mutate the array to generate each permutation, `Combinations` only
 has `Sequence` conformance. Adding `Collection` conformance would require
 storing the array in the index type, which would in turn lead to copying the
-array at every index advancement.
+array at every index advancement. `Combinations` does conform to
+`LazySequenceProtocol` when the base type conforms.
 
 ### Complexity
 

Guides/Cycle.md

@@ -33,10 +33,12 @@ extension Collection {
 ```
 
 The new `Cycle` type is a sequence only, given that the `Collection` protocol
-design makes infinitely large types impossible/impractical. Note that despite
-its name, the returned `FlattenSequence` will always have `Collection`
-conformance, and will have `BidirectionalCollection` conformance when called on
-a bidirectional collection.
+design makes infinitely large types impossible/impractical. `Cycle` also
+conforms to `LazySequenceProtocol` when the base type conforms.
+
+Note that despite its name, the returned `FlattenSequence` will always have
+`Collection` conformance, and will have `BidirectionalCollection` conformance
+when called on a bidirectional collection.
 
 ### Complexity
 

Guides/Indexed.md

@@ -30,5 +30,6 @@ extension Collection {
 ```
 
 `Indexed` scales from a collection up to a random-access collection, depending on 
-its base type.
+its base type. `Indexed` also conforms to `LazySequenceProtocol` when the base type
+conforms.
 

Guides/Permutations.md

@@ -75,7 +75,8 @@ Since the `Permutations` type needs to store an array of the collection’s
 indices and mutate the array to generate each permutation, `Permutations` only
 has `Sequence` conformance. Adding `Collection` conformance would require
 storing the array in the index type, which would in turn lead to copying the
-array at every index advancement.
+array at every index advancement. `Combinations` does conform to
+`LazySequenceProtocol` when the base type conforms.
 
 ### Complexity