title: How can I use C++14 features when building qmake projects?
body: <p>I'm currently using C++11 features in my Qt applications. However, I'd like to use some of the new C++14 features in my applications.</p>
  
  <p>To enable C++11 in a Qt application, one only needs to add one line in the <em>qmake</em> project file, namely:</p>
  
  <pre><code>CONFIG += c++11
  </code></pre>
  
  <p>or this for earlier versions:</p>
  
  <pre><code>QMAKE_CXXFLAGS += -std=c++1y
  </code></pre>
  
  <p>I already tried to do the same with C++14, but it didn't work. I changed the above mentioned line of the <em>qmake</em> project like this:</p>
  
  <pre><code>CONFIG += c++14
  </code></pre>
  
  <p>or this for earlier versions:</p>
  
  <pre><code>QMAKE_CXXFLAGS += -std=c++1y
  </code></pre>
  
  <p>After that, lots of compilation errors, that did not exist before, appear when trying to build the project. The project compiles fine, however, if I try to use any C++14 features, I get a compilation error. This is an example:</p>
  
  <pre><code>template&lt;typename T&gt;
  constexpr T pi = T(3.1415926535897932385);
  </code></pre>
  
  <p>This is the corresponding error:</p>
  
  <pre><code>main.cpp:7: error: template declaration of 'constexpr const T pi'
  constexpr T pi = T(3.1415926535897932385);  
            ^
  </code></pre>
  
  <p>How to enable C++14 features when using a <em>qmake</em> project in QtCreator?</p>
  
  <p>I am using Qt 5.3.2, Qt Creator 3.2.1, and MinGW 4.8.2 32 bit.</p>