Unfortunately, that ctor also takes a ControlType argument (defaulted), and calls the non-constexpr, non-inline function setControlType(). In order to make at least the two-arg version constexpr, I added a use of the ternary operator to check for type == DefaultType, making all calls of the ctor that use type == DefaultType constexpr. For init'ing an aggregate type without ctor in the ctor-init-list, I needed to require uniform initialization, too. C++11-style constexpr cannot call void functions, so I needed to extract the transformation part of setControlType() into a new function that returns the result instead of storing it directly. Saves a surprising 2K in QtWidgets text size on GCC 4.9, AMD64 Linux stripped release builds. Change-Id: Ib4adf5fd6e54d5345dbfe1c298554278faf13c58 Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>