Re: Compile time vs runtime?

From:
=?iso-8859-1?q?Erik_Wikstr=F6m?= <eriwik@student.chalmers.se>
Newsgroups:
comp.lang.c++
Date:
9 May 2007 03:58:53 -0700
Message-ID:
<1178708333.350105.64670@o5g2000hsb.googlegroups.com>
On 9 Maj, 11:28, desktop <f...@sss.com> wrote:

I have read that using templates makes types know at compile time and
using inheritance the types are first decided at runtime. The use of
pointers and casts also indicates that the types will first be know at
runtime.


Don't know if this answers your question or not; the idea behind
templates it that you at compile-time knows all the types that can be
used, and then generate code for each of those types. That's why it's
called templates, since it's not the code you write that gets executed
since it's just a template used by the compiler to generate the code
that will be executed.

But is there some strict definitions that defines runtime code and
compile time code that can be used in general?


Compile-time is compile-time, meaning that all the magic takes place
before the application is compiled, which is about as typesafe as you
can get. With runtime the magic happens when needed and have not been
fully checked at compilation. This means that for compile-time
polymorphism you need to know most if not everything about the types
at compile-time, which is why you can't have containers that can be
used with any type as compiled code, but have to distribute the source
(see the standard containers).

--
Erik Wikstr=F6m

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