Do const declarations help the compiler (GCC) produce faster code or are they only useful for readability and correctness?
Zed Shaw has argued that const is useless or is overused in C/C++:
Next is all the bizarre fascination with const. For some odd reason C++ loves to make you slap const on every part of a declaration, and yet I get the same end result as C: a function is called. (...)
(From: http://librelist.com/browser//mongrel2/2010/7/15/c-verses-c++/#770d94bcfc6ddf1d8510199996b607dd )