Add test to EnumMap too

Author: poypoyan

lib/std/enums.zig

@@ -792,7 +792,7 @@ pub fn EnumMap(comptime E: type, comptime V: type) type {
 
             pub fn next(self: *Iterator) ?Entry {
                 return if (self.inner.next()) |index|
-                    Entry{
+                    .{
                         .key = Indexer.keyForIndex(index),
                         .value = &self.values[index],
                     }
@@ -816,6 +816,19 @@ test EnumMap {
     try testing.expectEqual(0x80, some.get(.blue));
 }
 
+test "EnumMap iterator for one field" {
+    const Enum0 = std.meta.FieldEnum(struct { x: u32 });
+    const Enum1 = enum { x };
+
+    var a = std.EnumMap(Enum0, u32).initFull(123);
+    var it0 = a.iterator();
+    try testing.expectEqual(it0.next().?.key, Enum0.x);
+
+    var b = std.EnumMap(Enum1, u32).initFull(123);
+    var it1 = b.iterator();
+    try testing.expectEqual(it1.next().?.key, Enum1.x);
+}
+
 /// A multiset of enum elements up to a count of usize. Backed
 /// by an EnumArray. This type does no dynamic allocation and can
 /// be copied by value.
@@ -1292,7 +1305,7 @@ pub fn EnumArray(comptime E: type, comptime V: type) type {
             key: Key,
 
             /// A pointer to the value in the array associated
-            /// with this key. Modifications through this
+            /// with this key.  Modifications through this
             /// pointer will modify the underlying data.
             value: *Value,
         };