pkg/macos: support CFCharacterSet

pkg/macos/foundation.zig

@@ -2,6 +2,7 @@ pub const c = @import("foundation/c.zig");
 pub usingnamespace @import("foundation/array.zig");
 pub usingnamespace @import("foundation/attributed_string.zig");
 pub usingnamespace @import("foundation/base.zig");
+pub usingnamespace @import("foundation/character_set.zig");
 pub usingnamespace @import("foundation/data.zig");
 pub usingnamespace @import("foundation/dictionary.zig");
 pub usingnamespace @import("foundation/number.zig");

pkg/macos/foundation/character_set.zig

@@ -0,0 +1,30 @@
+const std = @import("std");
+const assert = std.debug.assert;
+const Allocator = std.mem.Allocator;
+const foundation = @import("../foundation.zig");
+const c = @import("c.zig");
+
+pub const CharacterSet = opaque {
+    pub fn createWithCharactersInString(
+        str: *foundation.String,
+    ) Allocator.Error!*CharacterSet {
+        return @intToPtr(?*CharacterSet, @ptrToInt(c.CFCharacterSetCreateWithCharactersInString(
+            null,
+            @ptrCast(c.CFStringRef, str),
+        ))) orelse Allocator.Error.OutOfMemory;
+    }
+
+    pub fn release(self: *CharacterSet) void {
+        c.CFRelease(self);
+    }
+};
+
+test "character set" {
+    //const testing = std.testing;
+
+    const str = try foundation.String.createWithBytes("hello world", .ascii, false);
+    defer str.release();
+
+    const cs = try CharacterSet.createWithCharactersInString(str);
+    defer cs.release();
+}