//build – is now the time to dust off my C++?
There’s lots of sessions at build on C++. This is kind of interesting, for a long time C++ has been slipping into the background whilst the .NET languages have taken all the limelight and the lions share of investment.
Given that WinRT is developed in C++, it seems pretty apparent that the level of interop for .NET Metro style apps will be greatly increased, the performance implication of this is not clear yet.
The key notes at build made several references to the fact that calls to the WinRT are simply vtable lookups, clearly whilst this is the case for C++ apps (well almost, from memory there is an indirection when using COM in order to get to the vtable) it is not the case for managed apps, you will end up with more instructions (due to the level of interop).
Regardless of any performance hit, managed languages undeniably offer greater productivity and the performance hit in most scenarios will not warrant the need to write the app in C++. But, if you want to squeeze the most performance out of your WinRT app it will need to be developed in C++.
