passing values to a function c++

A pointer. Or a reference if you're using C++.

Quote:

Original post by Captain Logic A pointer. Or a reference if you're using C++.

Unless the structure is very small (at least anything under 4 bytes, maybe up to as big as 8).

Unless the structure is very big, you probably won't _see_ a preformance difference either way.

Unless the structure's very small (under 4 bytes), then it will actually be slower to pass a reference or pointer (but, with padding, I don't think that ever happens). If the structure's over 4 bytes, then it will be faster on all 32-bit machines and compilers.

If the structure is a POD, both methods will be equivalent for small structures, and it will be faster to pass the structure by reference if it is big.

For non-POD types, everything depends on the complexity of the copy constructor, but generally passing by reference is preferred.

If the function has a side-effect, such as storing the structure for later use, it is preferable to pass it either by value or by a smart shared pointer (see boost::shared_ptr).