title: AndroidStudio/Kotlin - Unresolved reference: ReadWriteProperty - Kotlin version 1.0.0-beta-1038
body: <p>I have a working Android project using Kotlin version 1.0.0-beta-1038 in Android Studio.</p>
  
  <p>I can run it using Kotlin in different parts, it compiles and works in the emulator but when I tried to use ReadWriteProperty it gives this error message:</p>
  
  <p><strong>Unresolved reference: ReadWriteProperty</strong></p>
  
  <p><a href="https://i.stack.imgur.com/l4vHt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/l4vHt.png" alt="Unresolved reference: ReadWriteProperty"></a></p>
  
  <p>Class called PreferenceUtils.kt:</p>
  
  <p><a href="https://i.stack.imgur.com/AG0e8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AG0e8.png" alt="enter image description here"></a></p>
  
  <p>build.grade (Module: app)</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  
  android {
      compileSdkVersion 23
      buildToolsVersion "23.0.1"
  
      defaultConfig {
          applicationId "com.droidcba.oculto"
          minSdkVersion 16
          targetSdkVersion 23
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
      sourceSets {
          main.java.srcDirs += 'src/main/kotlin'
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      testCompile 'junit:junit:4.12'
      compile 'com.android.support:appcompat-v7:23.0.1'
      compile 'com.android.support:design:23.0.1'
      compile 'com.android.support:recyclerview-v7:23.0.1'
  
      compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
  
      compile 'com.squareup.retrofit:retrofit:2.0.0-beta1'
      compile 'com.squareup.retrofit:adapter-rxjava:2.0.0-beta1'
      compile 'com.squareup.retrofit:converter-gson:2.0.0-beta1'
  
      compile 'io.reactivex:rxandroid:1.0.1'
      compile 'io.reactivex:rxjava:1.0.14'
  }
  
  buildscript {
      ext.kotlin_version = '1.0.0-beta-1038'
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
          classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
      }
  }
  
  repositories {
      mavenCentral()
  }
  </code></pre>
  
  <p>build.grade (Module: myProject)</p>
  
  <pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:1.3.0'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  allprojects {
      repositories {
          jcenter()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>Please let me know if you need more info. Thanks!</p>