When should I use __forceinline instead of inline?

Question

Visual Studio includes support for __forceinline. The Microsoft Visual Studio 2005 documentation states:

The __forceinline keyword overrides the co

Answer 1

Actually, even with the __forceinline keyword. Visual C++ sometimes chooses not to inline the code. (Source: Resulting assembly source code.)

Always look at the resulting assembly code where speed is of importance (such as tight inner loops needed to be run on each frame).

Sometimes using #define instead of inline will do the trick. (of course you loose a lot of checking by using #define, so use it only when and where it really matters).