[add] first

Libraries/com.unity.services.core/Runtime/Device/UserIdProviders/NSUserDefaults.mm

@@ -0,0 +1,36 @@
+#include <string>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+char* UOCPUserDefaultsGetString(const char *key) {
+    if (!key) {
+        return nil;
+    }
+    NSString* stringKey = [NSString stringWithUTF8String:key];
+    NSString* stringValue = [[NSUserDefaults standardUserDefaults] stringForKey:stringKey];
+    if (!stringValue) {
+        return nil;
+    }
+    return strdup([stringValue UTF8String]);
+}
+
+void UOCPUserDefaultsSetString(const char *key, const char *value) {
+    if (!key) {
+        return;
+    }
+    NSString* stringKey = [NSString stringWithUTF8String:key];
+    if (!value)
+    {
+        [[NSUserDefaults standardUserDefaults] removeObjectForKey:stringKey];
+    } else {
+        NSString* stringValue = [NSString stringWithUTF8String:value];
+        [[NSUserDefaults standardUserDefaults] setValue:stringValue forKey:stringKey];
+    }
+    [[NSUserDefaults standardUserDefaults] synchronize];
+}
+
+#ifdef __cplusplus
+}
+#endif