title: Visual Studio 2019 is raising warnings about structures having variables without default values
body: <p>Take this structure definition:</p>
  <pre class="lang-cpp prettyprint-override"><code>typedef struct tagReferenceMWB
  {
      COleDateTime datStartDate;
      COleDateTime datEndDate;
      COleDateTime datFirstMonday;
      COleDateTime datLastMonday;
      CString      strFileMWB;
      WORD         wCount;
      bool         bReferenced;
      bool         bModified;
  
  } S_REFERENCE_MWB;
  </code></pre>
  <p>The compiler in VS2019 is issuing a warning:</p>
  <p><a href="https://i.stack.imgur.com/vwEW6.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vwEW6.jpg" alt="Warning" /></a></p>
  <blockquote>
  <pre><code>Warning   C26495  Variable 'CChristianLifeMinistryDefines::tagReferenceMWB::bModified' is uninitialized. Always initialize a member variable (type.6).    Meeting Schedule Assistant  d:\my programs\2019\meetschedassist\meeting schedule assistant\christianlifeministrydefines.h   348 
  Warning   C26495  Variable 'CChristianLifeMinistryDefines::tagReferenceMWB::bReferenced' is uninitialized. Always initialize a member variable (type.6).  Meeting Schedule Assistant  d:\my programs\2019\meetschedassist\meeting schedule assistant\christianlifeministrydefines.h   348 
  Warning   C26495  Variable 'CChristianLifeMinistryDefines::tagReferenceMWB::wCount' is uninitialized. Always initialize a member variable (type.6).       Meeting Schedule Assistant  d:\my programs\2019\meetschedassist\meeting schedule assistant\christianlifeministrydefines.h   348 
  </code></pre>
  </blockquote>
  <p>Since we can't assign default values in a structure definition how do we resolve the issue?</p>
  <h1>Update</h1>
  <p>Based on the comments in the supplied answer I have check my project settings:</p>
  <p><a href="https://i.stack.imgur.com/f970m.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/f970m.jpg" alt="C++ Language" /></a></p>
  <p>My project started life over 10 years ago and this setting appears to be <strong>empty</strong>. I do not know the significance is of this being left blank? These are the options I have:</p>
  <p><a href="https://i.stack.imgur.com/qH1h0.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qH1h0.jpg" alt="C++ Language Options" /></a></p>
  <p>What is the significant impact of changing the value to <strong>C++14</strong> or <strong>C++17</strong>? IE. will it affect what operating systems it can run on?</p>