How to properly use qRegisterMetaType with multidimensional arrays? <p>I want to use something like</p> <pre><code>typedef double Matrix[4][4]; </code></pre> <p>to represent transformations and also pass them around with the QT signal/slot mechanism. But when I use</p> <pre><code>Q_DECLARE_METATYPE(Matrix) </code></pre> <p>it throws an error in qmetatype.h at this function</p> <pre><code>void *qMetaTypeConstructHelper(const T *t) { if (!t) return new T(); return new T(*static_cast&lt;const T*&gt;(t)); } </code></pre> <p>saying: "error C2075: 'Target of operator new()' : array initialization needs curly braces"</p>