This might actually be slightly less off topic than the previous post, because it parallels the way that I think about that condition::wait method... Anyway, I'm curious what people think about: void perverse_strcpy( const char *src, char *dest, const char *done // note const ) { while (!done) { // note we expect change *dest++ = *src++; } } The caller can do something like: src = "hello world"; dest[strlen(src)] = 1; // store a nonzero value perverse_strcpy(src, dest, dest+strlen(src)); Yes, its a kinda stupid and, well, dubious function. However, the point is that "const char *" simply means that the pointer points to a char that can only be accessed as a "const char" through that pointer. It does not imply that the referenced thing is physically const. Nor does it imply that the referenced thing is logically const. (meaning that non-const methods can still be called on an object that has a "const Foo *" pointing to it; they simply can't be called through that pointer.) Does this run counter to what people believe the semantics of "const char *" to be? Are compilers permitted to optimize out the check of "!done" based on const-ness? (IIRC, they actually may in some related examples, if "src" and "dest" are types that should not alias to "done"; but this is not the case here) Is there any undefined or implementation-defined behavior of the above code? As separate aside, I believe that "physically const" refers specifically to a property of an object, say, the string constant "x". It is the reason why: const_cast("x")[0] = 'y' ... results in undefined behavior. The const keyword _could_ be used on an interface to indicate that a method will not produce undefined behavior when invoked on an instance that is actually physically const. This is different from using the const keyword to identify methods which maintain "logical constness". The latter meaning (whatever that may be) is what I believe is used in practice. (and the language is, I believe, designed to support this other meaning) Of course, I'm not, in some cases, sure what that meaning is! I suspect, by the way, that different people may have different ideas of how the const keyword should be applied to interfaces in practice. Each person might have an internally consistent viewpoint, but there may still be several mutually incompatible views. (I'm pretty sure that there are at least a few. I hope they are not as "notoriously arbitrary" :) as naming conventions!) Lastly, just because it amuses me: C++ Shrink: How does that const Foo * make you feel? Programmer: I feel frustrated, doc! I want to change things, but I can't. I know that the other coders do things that I can't; I can see all the changes that they make! Why not me? C++ Shrink: Hmm. Interesting. Weston Markham