Re: Some errors in MIT's intro C++ course
On Sep 17, 3:23 pm, Jorgen Grahn <grahn+n...@snipabacken.se> wrote:
On Fri, 2010-09-17, Juha Nieminen wrote:
In comp.lang.c++ Jorgen Grahn <grahn+n...@snipabacken.se> wrote:
I have never, ever used a bounds-checking std::vector<T>::operator[].
And I have never seen others use it, either. I rely on it to be as
fast as C array indexing.
I don't think you understand. operator[] will have
bound-checking when compiling in *debug* mode (with VC++ and
some other compilers), not when compiling in *release* mode.
Quoted out of context it may seem as if I don't understand, but I
believe I do. I was responding to this:
and it is also the
commonly preferred form in "real" code, not only in exercises at
university.
and my observation was simply that I have never seen that
being done in real life.
:-)
Put that way...
There may be some disagreement as to what is meant by "in real
life", or "commonly prefered". We all know that there's an
awful lot of bad code being written, and that a lot of
programmers are too concerned about performance when it is not
an issue. (The same programmers, by the way, tend to write very
poorly performing programs when performance is an issue.) So
the issue is whether we're talking about the real life over the
set of all programmers, or only over the set of competent
programmers working in well managed environments. Competent C++
programmers commonly prefer leaving bounds checking in when
delivering their product. (If they can afford the runtime
overhead.)
--
James Kanze