🚀 go-pugleaf

On Mon, 4 Sep 2006 23:56:06 +0200, "Muchomor"
<muchomor_w_kropkiCUT_THIS@gazeta.pl> wrote:

 
>
>Wytknijcie mi gdzie sie myle, ale dla mnie ten fragment nie ma krzty sensu. 
>Autor tutaj najwyrazniej strzela sobie samoboja. Jesli przyjac - za 
>autorem - , ze kompilator stosujac copy&paste z czegos takeigo :
>
>template<typename T> void Fun(T val)
>{
>    std::cout << "Val = " << val << "\n";
>}
>
>wygeneruje np. 2 funkcje
>
>void Fun(int  val);    (1)
>void Fun(double val); (2)
>
>to gdzie tu szablony "hurt the C++ compiler's ability to generate efficient 
>code" ?
>Czym sie to bedzie roznic od sytuacji gdy programista sam sobie napisze 
>funkcje (1) i (2) zamiast szablonu?
>Kompilator bedzie szczesliwszy? Nie sadze..

Tak jest w Javie. A jak jest w C++?...

A.L.


"You might imagine that List<Integer> stands for a version of List
where E has been uniformly replaced by Integer:

public interface IntegerList { void add(Integer x)
Iterator<Integer> iterator();
}

This intuition can be helpful, but it’s also misleading.
It is helpful, because the parameterized type List<Integer> does
indeed have methods that look just like this expansion.

It is misleading, because the declaration of a generic is never
actually expanded in this way. There aren’t multiple copies of the
code: not in source, not in binary, not on disk and not in memory.
If you are a C++ programmer, you’ll understand that this is
very different than a C++ template. 

A generic type declaration is compiled once and for all, and turned
into a single class file, just like an ordinary class or interface
declaration. Type parameters are analogous to the ordinary
parameters used in methods or constructors.
Much like a method has formal value parameters that describe the
kinds of values it operates on, a generic declaration has formal
type parameters. When a method is invoked, actual arguments are
substituted for the formal parameters, and the method body is
evaluated. When a generic declaration is invoked, the actual type
arguments are substituted for the formal type parameters..."