You are missing my point. It can store it's own length, but the compiler will still not be aware of the length, except in a real local context (i.e. in the sam

You are missing my point. It can store it's own length, but the compiler will still not be aware of the length, except in a real local context (i.e. in the same block of code, either actually, or via inlining). So if you decide to loop over your array, you have to pay the price of looping (jumping and comparing). If you know that you are working with an array of fixed length, and you use a C++ std::array, you can pass this by reference to functions and those functions will know at compile time how long the array is. So you don't have to pay for looping at all; if you do something small in a loop the compiler will unroll it to 3 assignments or what not. In addition, the reason that C programmers don't build their own abstractions is because C does not have templates. So building your own abstraction either means that it's not very abstract (i.e. restricted to one data type), or you are using void, or macros, or both. These things are all horrible to work with, void based data structures also involve a performance hit. This tilts the trade-off between writing abstraction and single-use code far, far towards the latter. In C++ you have templates which are far better for writing your own data structure than macros, and have no performance penalty.