diff --git a/js/js.libraries/src/core/generated/_ArraysJs.kt b/js/js.libraries/src/core/generated/_ArraysJs.kt
index aa42608fd01..d7b13651452 100644
--- a/js/js.libraries/src/core/generated/_ArraysJs.kt
+++ b/js/js.libraries/src/core/generated/_ArraysJs.kt
@@ -8880,72 +8880,63 @@ public inline fun CharArray.all(predicate: (Char) -> Boolean): Boolean {
  * Returns `true` if array has at least one element.
  */
 public fun <T> Array<out T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun ByteArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun ShortArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun IntArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun LongArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun FloatArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun DoubleArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun BooleanArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun CharArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
@@ -10634,72 +10625,63 @@ public fun CharArray.minWith(comparator: Comparator<in Char>): Char? {
  * Returns `true` if the array has no elements.
  */
 public fun <T> Array<out T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun ByteArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun ShortArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun IntArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun LongArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun FloatArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun DoubleArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun BooleanArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun CharArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
diff --git a/js/js.libraries/src/core/generated/_CollectionsJs.kt b/js/js.libraries/src/core/generated/_CollectionsJs.kt
index 7f55d417a78..047194d88eb 100644
--- a/js/js.libraries/src/core/generated/_CollectionsJs.kt
+++ b/js/js.libraries/src/core/generated/_CollectionsJs.kt
@@ -1361,6 +1361,7 @@ public infix fun <T> Iterable<T>.union(other: Iterable<T>): Set<T> {
  * Returns `true` if all elements match the given [predicate].
  */
 public inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return true
     for (element in this) if (!predicate(element)) return false
     return true
 }
@@ -1369,14 +1370,15 @@ public inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean {
  * Returns `true` if collection has at least one element.
  */
 public fun <T> Iterable<T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    if (this is Collection) return !isEmpty()
+    return iterator().hasNext()
 }
 
 /**
  * Returns `true` if at least one element matches the given [predicate].
  */
 public inline fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return false
     for (element in this) if (predicate(element)) return true
     return false
 }
@@ -1385,6 +1387,7 @@ public inline fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean {
  * Returns the number of elements in this collection.
  */
 public fun <T> Iterable<T>.count(): Int {
+    if (this is Collection) return size
     var count = 0
     for (element in this) count++
     return count
@@ -1402,6 +1405,7 @@ public inline fun <T> Collection<T>.count(): Int {
  * Returns the number of elements matching the given [predicate].
  */
 public inline fun <T> Iterable<T>.count(predicate: (T) -> Boolean): Int {
+    if (this is Collection && isEmpty()) return 0
     var count = 0
     for (element in this) if (predicate(element)) count++
     return count
@@ -1653,14 +1657,15 @@ public fun <T> Iterable<T>.minWith(comparator: Comparator<in T>): T? {
  * Returns `true` if the collection has no elements.
  */
 public fun <T> Iterable<T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    if (this is Collection) return isEmpty()
+    return !iterator().hasNext()
 }
 
 /**
  * Returns `true` if no elements match the given [predicate].
  */
 public inline fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return true
     for (element in this) if (predicate(element)) return false
     return true
 }
diff --git a/js/js.libraries/src/core/generated/_MapsJs.kt b/js/js.libraries/src/core/generated/_MapsJs.kt
index 02da5b759f7..29690bd3bd6 100644
--- a/js/js.libraries/src/core/generated/_MapsJs.kt
+++ b/js/js.libraries/src/core/generated/_MapsJs.kt
@@ -88,6 +88,7 @@ public inline fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.mapTo(des
  * Returns `true` if all entries match the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.all(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return true
     for (element in this) if (!predicate(element)) return false
     return true
 }
@@ -96,14 +97,14 @@ public inline fun <K, V> Map<out K, V>.all(predicate: (Map.Entry<K, V>) -> Boole
  * Returns `true` if map has at least one entry.
  */
 public fun <K, V> Map<out K, V>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if at least one entry matches the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.any(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return false
     for (element in this) if (predicate(element)) return true
     return false
 }
@@ -120,6 +121,7 @@ public inline fun <K, V> Map<out K, V>.count(): Int {
  * Returns the number of entries matching the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.count(predicate: (Map.Entry<K, V>) -> Boolean): Int {
+    if (isEmpty()) return 0
     var count = 0
     for (element in this) if (predicate(element)) count++
     return count
@@ -167,14 +169,14 @@ public fun <K, V> Map<out K, V>.minWith(comparator: Comparator<in Map.Entry<K, V
  * Returns `true` if the map has no entries.
  */
 public fun <K, V> Map<out K, V>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if no entries match the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.none(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return true
     for (element in this) if (predicate(element)) return false
     return true
 }
diff --git a/js/js.libraries/src/core/generated/_SequencesJs.kt b/js/js.libraries/src/core/generated/_SequencesJs.kt
index 061ab04feb4..31d3bb14bb7 100644
--- a/js/js.libraries/src/core/generated/_SequencesJs.kt
+++ b/js/js.libraries/src/core/generated/_SequencesJs.kt
@@ -936,8 +936,7 @@ public inline fun <T> Sequence<T>.all(predicate: (T) -> Boolean): Boolean {
  * The operation is _terminal_.
  */
 public fun <T> Sequence<T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return iterator().hasNext()
 }
 
 /**
@@ -1215,8 +1214,7 @@ public fun <T> Sequence<T>.minWith(comparator: Comparator<in T>): T? {
  * The operation is _terminal_.
  */
 public fun <T> Sequence<T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return !iterator().hasNext()
 }
 
 /**
diff --git a/js/js.libraries/src/core/generated/_StringsJs.kt b/js/js.libraries/src/core/generated/_StringsJs.kt
index 4cc6b649cd0..356ad697cde 100644
--- a/js/js.libraries/src/core/generated/_StringsJs.kt
+++ b/js/js.libraries/src/core/generated/_StringsJs.kt
@@ -815,8 +815,7 @@ public inline fun CharSequence.all(predicate: (Char) -> Boolean): Boolean {
  * Returns `true` if char sequence has at least one character.
  */
 public fun CharSequence.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
@@ -1003,8 +1002,7 @@ public fun CharSequence.minWith(comparator: Comparator<in Char>): Char? {
  * Returns `true` if the char sequence has no characters.
  */
 public fun CharSequence.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
diff --git a/libraries/stdlib/src/generated/_Arrays.kt b/libraries/stdlib/src/generated/_Arrays.kt
index e3a4869d71b..ae33efda44f 100644
--- a/libraries/stdlib/src/generated/_Arrays.kt
+++ b/libraries/stdlib/src/generated/_Arrays.kt
@@ -8950,72 +8950,63 @@ public inline fun CharArray.all(predicate: (Char) -> Boolean): Boolean {
  * Returns `true` if array has at least one element.
  */
 public fun <T> Array<out T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun ByteArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun ShortArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun IntArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun LongArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun FloatArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun DoubleArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun BooleanArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if array has at least one element.
  */
 public fun CharArray.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
@@ -10704,72 +10695,63 @@ public fun CharArray.minWith(comparator: Comparator<in Char>): Char? {
  * Returns `true` if the array has no elements.
  */
 public fun <T> Array<out T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun ByteArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun ShortArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun IntArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun LongArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun FloatArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun DoubleArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun BooleanArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if the array has no elements.
  */
 public fun CharArray.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
diff --git a/libraries/stdlib/src/generated/_Collections.kt b/libraries/stdlib/src/generated/_Collections.kt
index d622d6315ca..63f0fed44e6 100644
--- a/libraries/stdlib/src/generated/_Collections.kt
+++ b/libraries/stdlib/src/generated/_Collections.kt
@@ -1371,6 +1371,7 @@ public infix fun <T> Iterable<T>.union(other: Iterable<T>): Set<T> {
  * Returns `true` if all elements match the given [predicate].
  */
 public inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return true
     for (element in this) if (!predicate(element)) return false
     return true
 }
@@ -1379,14 +1380,15 @@ public inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean {
  * Returns `true` if collection has at least one element.
  */
 public fun <T> Iterable<T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    if (this is Collection) return !isEmpty()
+    return iterator().hasNext()
 }
 
 /**
  * Returns `true` if at least one element matches the given [predicate].
  */
 public inline fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return false
     for (element in this) if (predicate(element)) return true
     return false
 }
@@ -1395,6 +1397,7 @@ public inline fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean {
  * Returns the number of elements in this collection.
  */
 public fun <T> Iterable<T>.count(): Int {
+    if (this is Collection) return size
     var count = 0
     for (element in this) count++
     return count
@@ -1412,6 +1415,7 @@ public inline fun <T> Collection<T>.count(): Int {
  * Returns the number of elements matching the given [predicate].
  */
 public inline fun <T> Iterable<T>.count(predicate: (T) -> Boolean): Int {
+    if (this is Collection && isEmpty()) return 0
     var count = 0
     for (element in this) if (predicate(element)) count++
     return count
@@ -1663,14 +1667,15 @@ public fun <T> Iterable<T>.minWith(comparator: Comparator<in T>): T? {
  * Returns `true` if the collection has no elements.
  */
 public fun <T> Iterable<T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    if (this is Collection) return isEmpty()
+    return !iterator().hasNext()
 }
 
 /**
  * Returns `true` if no elements match the given [predicate].
  */
 public inline fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean {
+    if (this is Collection && isEmpty()) return true
     for (element in this) if (predicate(element)) return false
     return true
 }
diff --git a/libraries/stdlib/src/generated/_Maps.kt b/libraries/stdlib/src/generated/_Maps.kt
index a8f932d3dda..d11c03b317a 100644
--- a/libraries/stdlib/src/generated/_Maps.kt
+++ b/libraries/stdlib/src/generated/_Maps.kt
@@ -88,6 +88,7 @@ public inline fun <K, V, R, C : MutableCollection<in R>> Map<out K, V>.mapTo(des
  * Returns `true` if all entries match the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.all(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return true
     for (element in this) if (!predicate(element)) return false
     return true
 }
@@ -96,14 +97,14 @@ public inline fun <K, V> Map<out K, V>.all(predicate: (Map.Entry<K, V>) -> Boole
  * Returns `true` if map has at least one entry.
  */
 public fun <K, V> Map<out K, V>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
  * Returns `true` if at least one entry matches the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.any(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return false
     for (element in this) if (predicate(element)) return true
     return false
 }
@@ -120,6 +121,7 @@ public inline fun <K, V> Map<out K, V>.count(): Int {
  * Returns the number of entries matching the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.count(predicate: (Map.Entry<K, V>) -> Boolean): Int {
+    if (isEmpty()) return 0
     var count = 0
     for (element in this) if (predicate(element)) count++
     return count
@@ -167,14 +169,14 @@ public fun <K, V> Map<out K, V>.minWith(comparator: Comparator<in Map.Entry<K, V
  * Returns `true` if the map has no entries.
  */
 public fun <K, V> Map<out K, V>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
  * Returns `true` if no entries match the given [predicate].
  */
 public inline fun <K, V> Map<out K, V>.none(predicate: (Map.Entry<K, V>) -> Boolean): Boolean {
+    if (isEmpty()) return true
     for (element in this) if (predicate(element)) return false
     return true
 }
diff --git a/libraries/stdlib/src/generated/_Sequences.kt b/libraries/stdlib/src/generated/_Sequences.kt
index 3afc3105f85..246947e234d 100644
--- a/libraries/stdlib/src/generated/_Sequences.kt
+++ b/libraries/stdlib/src/generated/_Sequences.kt
@@ -958,8 +958,7 @@ public inline fun <T> Sequence<T>.all(predicate: (T) -> Boolean): Boolean {
  * The operation is _terminal_.
  */
 public fun <T> Sequence<T>.any(): Boolean {
-    for (element in this) return true
-    return false
+    return iterator().hasNext()
 }
 
 /**
@@ -1237,8 +1236,7 @@ public fun <T> Sequence<T>.minWith(comparator: Comparator<in T>): T? {
  * The operation is _terminal_.
  */
 public fun <T> Sequence<T>.none(): Boolean {
-    for (element in this) return false
-    return true
+    return !iterator().hasNext()
 }
 
 /**
diff --git a/libraries/stdlib/src/generated/_Strings.kt b/libraries/stdlib/src/generated/_Strings.kt
index ec9305b2bfb..b2adb7cf962 100644
--- a/libraries/stdlib/src/generated/_Strings.kt
+++ b/libraries/stdlib/src/generated/_Strings.kt
@@ -823,8 +823,7 @@ public inline fun CharSequence.all(predicate: (Char) -> Boolean): Boolean {
  * Returns `true` if char sequence has at least one character.
  */
 public fun CharSequence.any(): Boolean {
-    for (element in this) return true
-    return false
+    return !isEmpty()
 }
 
 /**
@@ -1011,8 +1010,7 @@ public fun CharSequence.minWith(comparator: Comparator<in Char>): Char? {
  * Returns `true` if the char sequence has no characters.
  */
 public fun CharSequence.none(): Boolean {
-    for (element in this) return false
-    return true
+    return isEmpty()
 }
 
 /**
diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
index 23fa64a8cec..539b4a4d93c 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
@@ -10,8 +10,13 @@ fun aggregates(): List<GenericFunction> {
         inline(true)
         doc { f -> "Returns `true` if all ${f.element.pluralize()} match the given [predicate]." }
         returns("Boolean")
-        body {
+        body { f ->
             """
+            ${when (f) {
+                Iterables -> "if (this is Collection && isEmpty()) return true"
+                Maps -> "if (isEmpty()) return true"
+                else -> ""
+            }}
             for (element in this) if (!predicate(element)) return false
             return true
             """
@@ -24,8 +29,13 @@ fun aggregates(): List<GenericFunction> {
 
         doc { f -> "Returns `true` if no ${f.element.pluralize()} match the given [predicate]." }
         returns("Boolean")
-        body {
+        body { f ->
             """
+            ${when (f) {
+                Iterables -> "if (this is Collection && isEmpty()) return true"
+                Maps -> "if (isEmpty()) return true"
+                else -> ""
+            }}
             for (element in this) if (predicate(element)) return false
             return true
             """
@@ -37,11 +47,17 @@ fun aggregates(): List<GenericFunction> {
         doc { f -> "Returns `true` if the ${f.collection} has no ${f.element.pluralize()}." }
         returns("Boolean")
         body {
+            "return !iterator().hasNext()"
+        }
+        body(Iterables) {
             """
-            for (element in this) return false
-            return true
+            if (this is Collection) return isEmpty()
+            return !iterator().hasNext()
             """
         }
+        body(Maps, CharSequences, ArraysOfObjects, ArraysOfPrimitives) {
+            "return isEmpty()"
+        }
         include(Maps, CharSequences)
     }
 
@@ -50,8 +66,13 @@ fun aggregates(): List<GenericFunction> {
 
         doc { f -> "Returns `true` if at least one ${f.element} matches the given [predicate]." }
         returns("Boolean")
-        body {
+        body { f ->
             """
+            ${when (f) {
+                Iterables -> "if (this is Collection && isEmpty()) return false"
+                Maps -> "if (isEmpty()) return false"
+                else -> ""
+            }}
             for (element in this) if (predicate(element)) return true
             return false
             """
@@ -63,11 +84,17 @@ fun aggregates(): List<GenericFunction> {
         doc { f -> "Returns `true` if ${f.collection} has at least one ${f.element}." }
         returns("Boolean")
         body {
+            "return iterator().hasNext()"
+        }
+        body(Iterables) {
             """
-            for (element in this) return true
-            return false
+            if (this is Collection) return !isEmpty()
+            return iterator().hasNext()
             """
         }
+        body(Maps, CharSequences, ArraysOfObjects, ArraysOfPrimitives) {
+            "return !isEmpty()"
+        }
         include(Maps, CharSequences)
     }
 
@@ -76,8 +103,13 @@ fun aggregates(): List<GenericFunction> {
 
         doc { f -> "Returns the number of ${f.element.pluralize()} matching the given [predicate]." }
         returns("Int")
-        body {
+        body { f ->
             """
+            ${when (f) {
+                Iterables -> "if (this is Collection && isEmpty()) return 0"
+                Maps -> "if (isEmpty()) return 0"
+                else -> ""
+            }}
             var count = 0
             for (element in this) if (predicate(element)) count++
             return count
@@ -89,8 +121,9 @@ fun aggregates(): List<GenericFunction> {
     templates add f("count()") {
         doc { f -> "Returns the number of ${f.element.pluralize()} in this ${f.collection}." }
         returns("Int")
-        body {
+        body { f ->
             """
+            ${if (f == Iterables) "if (this is Collection) return size" else "" }
             var count = 0
             for (element in this) count++
             return count