Singleton.html

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title: Singleton
layout: default
---
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            <span>Ruby on Rails 8.0.0</span><br />
        
        <div class="type">Module</div>
        <h1>
            Singleton
            
        </h1>
        <ul class="files">
            
            <li><a href="../files/activesupport/lib/active_support/core_ext/object/duplicable_rb.html">activesupport/lib/active_support/core_ext/object/duplicable.rb</a></li>
            
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    <h2 id="methods">Methods</h2>
    <ul>
      
        <li>
          <a href="#method-i-duplicable-3F">duplicable?</a>
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    <!-- Methods -->
    
    
      <h2 id="instance-public-methods">Instance Public methods</h2>
      
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          <h3 id="method-i-duplicable-3F">
            
              duplicable?()
            
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            <div class="description">
              <p><a href="Singleton.html"><code>Singleton</code></a> instances are not duplicable:</p>

<pre><code>Class.new.include(Singleton).instance.dup # TypeError (can&#39;t dup instance of singleton
</code></pre>
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            <details class="method__source">
              <summary>
                <span class="label">📝 Source code</span>
              </summary>

              <pre><code class="ruby"># File activesupport/lib/active_support/core_ext/object/duplicable.rb, line 66
  def duplicable?
    false
  end</code></pre>
              
                <a href="https://github.com/rails/rails/blob/dd8f7185faeca6ee968a6e9367f6d8601a83b8db/activesupport/lib/active_support/core_ext/object/duplicable.rb#L66" target="_blank" class="github_url">🔎 See on GitHub</a>
              
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