On 2009-12-18 17:07:57 -0800, bearophile <bearophileh...@lycos.com> said:
Yigal Chripun:
.Net generics for example work by creating an instantiation for each
value type (same as c++ templates) and one instantiation for all
reference types since at the binary level all reference types are simply
addresses. C++ can't do this since it has no separation between
"structs" and "classes".
there is no casting involved since the full type info is stored.
so a Foo<Bar> will be typed as Foo<Bar> at the binary level as well and
you can use APIs to query this at runtime.
In D structs and classes are distinct enough, but they currently
produce duplicated templated code, this may be fixed:
void foo(T)(T o) {
printf("foo: %d\n", o.y);
}
class A { int x = 1; }
class B : A { int y = 2; }
class C : A { int y = 3; }
void main() {
B b = new B();
C c = new C();
foo(b);
foo(c);
}
/*
DMD1:
_D4temp17__T3fooTC4temp1BZ3fooFC4temp1BZv comdat
push EAX
mov ECX,offset FLAT:_D4temp1C6__vtblZ[018h]
push dword ptr 0Ch[EAX]
push ECX
call near ptr _printf
add ESP,8
pop EAX
ret
_D4temp17__T3fooTC4temp1CZ3fooFC4temp1CZv comdat
push EAX
mov ECX,offset FLAT:_D4temp1C6__vtblZ[018h]
push dword ptr 0Ch[EAX]
push ECX
call near ptr _printf
add ESP,8
pop EAX
ret
LDC:
_D13testtemplates27__T3fooTC13testtemplates1BZ3fooFC13testtemplates1BZv:
subl $12, %esp
movl 12(%eax), %eax
movl %eax, 4(%esp)
movl $.str3, (%esp)
call printf
addl $12, %esp
ret
_D13testtemplates27__T3fooTC13testtemplates1CZ3fooFC13testtemplates1CZv:
subl $12, %esp
movl 12(%eax), %eax
movl %eax, 4(%esp)
movl $.str3, (%esp)
call printf
addl $12, %esp
ret
*/
Bye,
bearophile
This isn't a bug. This is how it is template code is supposed to
work. However, there does seem to be one problem in the output you're
giving.
LDC should not be producing different name mangling than DMD! This is
part of the D ABI last I checked, so as to avoid all the problems C++
has associated with libraries from different compilers not playing nice.
-S
