Is this normally allowed in C++ or is it an MS language extension.

[gstercken]

You see a lot of this in MSDN. In some situations if you dont initialize a VARIANT in this manner (i.e. VARIANT v = {0}; ). Things don't work as you expect them to.

Well, that's obvious: VARIANT is a struct, so you can initialize the members of a VARIANT instance with an initializer list. The same can be done with the public members of a class, it's pretty much standard C++. However, the code sample you provided used a class without any members, that's why the comeau compiler complained.