StdlibUnittest: expose cartesianProduct() helper

Author: gribozavr

stdlib/private/StdlibCollectionUnittest/CheckCollectionType.swift.gyb

@@ -468,18 +468,6 @@ internal enum _SubSequenceSubscriptOnRangeMode {
   }
 }
 
-internal func _product<C1 : Collection, C2 : Collection>(
-  _ c1: C1, _ c2: C2
-) -> [(C1.Iterator.Element, C2.Iterator.Element)] {
-  var result: [(C1.Iterator.Element, C2.Iterator.Element)] = []
-  for e1 in c1 {
-    for e2 in c2 {
-      result.append((e1, e2))
-    }
-  }
-  return result
-}
-
 %{
   from gyb_stdlib_support import collectionForTraversal
   def testConstraints(protocol):
@@ -623,7 +611,7 @@ extension TestSuite {
         _blackHole(c[index])
       }
 
-      let tests = _product(
+      let tests = cartesianProduct(
         subscriptRangeTests,
         _SubSequenceSubscriptOnIndexMode.all)
 
@@ -722,7 +710,7 @@ extension TestSuite {
         _blackHole(c[index..<index])
       }
 
-      let tests = _product(
+      let tests = cartesianProduct(
         subscriptRangeTests,
         _SubSequenceSubscriptOnRangeMode.all)
 

stdlib/private/StdlibCollectionUnittest/CheckMutableCollectionType.swift.gyb

@@ -172,7 +172,7 @@ if resiliencyChecks.subscriptOnOutOfBoundsIndicesBehavior != .none {
     c[index] = wrapValue(OpaqueValue(9999))
   }
 
-  let tests = _product(
+  let tests = cartesianProduct(
     subscriptRangeTests,
     _SubSequenceSubscriptOnIndexMode.all)
 
@@ -325,7 +325,7 @@ if isFixedLengthCollection {
 }
 
 if resiliencyChecks.subscriptRangeOnOutOfBoundsRangesBehavior != .none {
-  let tests = _product(
+  let tests = cartesianProduct(
     subscriptRangeTests,
     _SubSequenceSubscriptOnRangeMode.all)
 

stdlib/private/StdlibUnittest/StdlibCoreExtras.swift

@@ -232,3 +232,16 @@ public func forAllPermutations<S : Sequence>(
     return ()
   }
 }
+
+public func cartesianProduct<C1 : Collection, C2 : Collection>(
+  _ c1: C1, _ c2: C2
+) -> [(C1.Iterator.Element, C2.Iterator.Element)] {
+  var result: [(C1.Iterator.Element, C2.Iterator.Element)] = []
+  for e1 in c1 {
+    for e2 in c2 {
+      result.append((e1, e2))
+    }
+  }
+  return result
+}
+