Sorry, I should have been more specific. C/C++ const has no effect on optimization, unless it's on a global/static object and the compiler can see the original

Sorry, I should have been more specific. C/C++ const has no effect on optimization, unless it's on a global/static object and the compiler can see the original declaration. I'm not going to look it up in the C++ spec, but in C it's only undefined behavior if the original object was const, and it would make sense for C++ to be the same.