Re: Length of C++ arrays allocated by operator new[]
Marcel M?ller <news.5.maazl@spamgourmet.com> wrote:
Use it for some dozen different types, not just int.
Use many functions of the STL containers not just the easiest ones.
Templates have to be instantiated for each unique parameter set. Even if
90% of the generated functions do not depend on all parameters or the
dependency ends once the compiler has done the type checks, the compiler
will generate distinct implementations. No programmer would repeat his
self that much without the templates (well, hopefully).
And exactly how would it be different from using non-templated code for
each used type? If you want an array of ints and an array of doubles,
you'll have to write twice as much code to handle those arrays. The only
difference with the templated version is that you will have to write the
code only once (it's the compiler that does the duplication rather than
yourself).
Your argument is as silly as saying "if I write two functions instead
of one, the size of the binary will increase". Of course it increases.
You are writing more code.
The question is, however, does the size of the code "explode" when you
use several types?
I understand "explosion" to mean that the size of the code increases
very significantly. Like if using one type would make the binary 5 kilobytes
but using two types would make it 100 kilobytes and using three would make
it 1 megabyte in size. That's an "explosion".
Well, rather than just theoretizing, I went and tried the example program
with two different types to see if the binary size "explodes". Or even
doubles:
//--------------------------------------------------
include <vector>
int main()
{
std::vector<int> array1(10000);
std::vector<short> array2(10000);
for(int i = 0; i < 10000; ++i) { array1[i] = i*3; array2[i] = i; }
int value = 0;
for(int i = 0; i < 10000; ++i) value += array1[i] + array2[i];
return value;
}
//--------------------------------------------------
The size of the executable? 5856 bytes.
Yeah, a true explosion in size.