� wrote:
this(this) is the copy constructor, I think.
this(this) is not the copy constructor. It is post-blit, which is useful
for when corrections need to be done after the automatic blitting:
http://digitalmars.com/d/2.0/struct.html#StructPostblit
Ali
(I am looking for rough corners in D, or in my knowledge of D.)
In this page:
http://www.digitalmars.com/d/2.0/templates-revisited.html
In the section Template Parameters there is written:
P:P*, // P must be a pointer type
-
So I have written this D2 program:
noboy wrote:
There was a soft link /bin/sh - dash
I have change this to bash, and now all went fine.
Thank you
Steven Schveighoffer Wrote:
On Thu, 18 Mar 2010 09:28:06 -0400, noboy nob...@nowhere.com wrote:
I was little bit surprise because
mkdir -p dmd-2/usr/{bin,lib,src/phobos2,share/man
On Fri, 19 Mar 2010 19:29:24 -0400, bearophile wrote:
(I am looking for rough corners in D, or in my knowledge of D.)
[..]
template IsPointer1(T) {
enum bool IsPointer1 = is(T : T*);
}
void main() {
int* ptr;
static assert(IsPointer1!(typeof(ptr))); // Err
}
But it
I created a struct, call it S, and some functions that operate on S. But I'm
confused about when const is useful.
Being an old Java programmer, I use 'const' the same as I used 'final' in Java.
So most of my functions look like this:
S for(const S a, const S b) {
S x = a;
S y = b;
Paul D. Anderson:
I created a struct, call it S, and some functions that operate on S. But
I'm confused about when const is useful.
Being an old Java programmer, I use 'const' the same as I used 'final' in
Java. So most of my functions look like this:
S for(const S a, const S b) {
Paul D. Anderson:
S x = cast(S) a;
S y = cast(S) b;
In Java (especially old Java) casts may be common, but in D they are something
that has to be used with care, don't cast away things carelessly :-)
Bye,
bearophile
bearophile Wrote:
Paul D. Anderson:
I created a struct, call it S, and some functions that operate on S. But
I'm confused about when const is useful.
Being an old Java programmer, I use 'const' the same as I used 'final' in
Java. So most of my functions look like this:
S
bearophile Wrote:
Paul D. Anderson:
S x = cast(S) a;
S y = cast(S) b;
In Java (especially old Java) casts may be common, but in D they are
something that has to be used with care, don't cast away things carelessly :-)
Bye,
bearophile
I realize that casting is a last resort
On 03/19/2010 07:53 PM, Moritz Warning wrote:
On Fri, 19 Mar 2010 19:29:24 -0400, bearophile wrote:
(I am looking for rough corners in D, or in my knowledge of D.)
[..]
template IsPointer1(T) {
enum bool IsPointer1 = is(T : T*);
}
void main() {
int* ptr;
static
Moritz Warning:
I think the problem is that is(T : T*) becomes is(int* : int**) and that's
false.
Thank you, you can be right.
So D docs are wrong, or that syntax has a semantic bug, or I have not
understood the situation yet.
If someone else has ideas I'm all ears.
-
Ellery
My guess is that:
struct S {
int x;
int[] a;
}
S foo(const S b) {
foo makes the promise that b's members won't change: so 'b.x' is
implicitely const(int) and 'b.a' is implicitely const(int[]).
S other = b;
Here you assign 'b.x', which is const(int), to 'other.x', which is int.
biozic:
I'm not sure if this is completely right nor if I'm completely clear,
though... :)
I think you are right.
In practice to copy something const to something that's not const you need a
deep copy function, because inside the array there can be other arrays that are
const, etc.
Transitive const requires transitive copy, it's easy :-)
Or when possible, you don't copy it, just return it.
Bye,
bearophile
So the question here is: do you know if there are important use cases for a
shallow_const attribute?
Bye,
bearophile
bearophile wrote:
(I am looking for rough corners in D, or in my knowledge of D.)
In this page:
http://www.digitalmars.com/d/2.0/templates-revisited.html
In the section Template Parameters there is written:
P:P*, // P must be a pointer type
-
So I have
Paul D. Anderson:
My struct has a dynamic array as a member -- that seems to be the problem.
This code doesn't compile:
struct S {
int x;
int[] a;
}
S foo(const S b) {
S other = b;
return other;
}
void main() {}
This compiles, oh joy:
struct S {
int x;
int[] a;
On Fri, 19 Mar 2010 20:58:21 -0400, Paul D. Anderson
paul.d.removet...@comcast.andthis.net wrote:
I created a struct, call it S, and some functions that operate on S.
But I'm confused about when const is useful.
Being an old Java programmer, I use 'const' the same as I used 'final'
in
After further review, I now realize that the right way (for me) to do this is
to add a .dup property. So instead of
S foo(const S s) {
S other;
other = s;
}
or
S foo(const S s) {
S other = S(s);
return other;
}
which didn't look right to me, I can write
S foo(const S s) {
Spacen Jasset wrote:
then presumably the syntax you are using is a bashism?. You could also
say something like:
system(bash mkdir -p ~ path);
Messing with your sh symlink may have some undesired consequences.
Actually, not messing with it will have undesired consequences. Lots of
bearophile wrote:
Operator overloading in D2 is not an easy thing, it needs training.
(That's why I have recently asked for the compiler to be strict to
avoid wrong usages of the operator overloading.)
I think the problem is really that it's still very buggy. In particular,
opAssign seems
Paul D. Anderson:
After further review, I now realize that the right way (for me) to do this is
to add a .dup property.
Steven Schveighoffer has given you quite good answers.
A dup is generally not enough, because what you dup can have other immutable
references nested inside. Dup is not a
Daniel Keep:
You do realise that Template Parameters are a completely different
thing to is expressions, right?
Nope. And from the other answers by Moritz and Ellery it seems I am not alone
:-)
You are right, this works:
template IsPointer1(T:T*) {
enum bool IsPointer1 = true;
}
template
Don:
I think the problem is really that it's still very buggy. In particular,
opAssign seems pretty defective. More importantly, struct constructors,
post blit, and struct destructors are still quite badly broken.
You are right, but in my opinion it's not just a matter of bugs. To solve real
Jesse Phillips Wrote:
Spacen Jasset wrote:
then presumably the syntax you are using is a bashism?. You could also
say something like:
system(bash mkdir -p ~ path);
Messing with your sh symlink may have some undesired consequences.
Actually, not messing with it will have
On 2010-03-20 00.29, bearophile wrote:
(I am looking for rough corners in D, or in my knowledge of D.)
In this page:
http://www.digitalmars.com/d/2.0/templates-revisited.html
In the section Template Parameters there is written:
P:P*, // P must be a pointer type
-
So
According to http://digitalmars.com/d/2.0/const3.html:
Const member functions are functions that are not allowed to change any
part of the object through the member function's this reference.
With the following code:
class Foo
{
Foo myFoo() const
{
On 21/03/10 00:18, bearophile wrote:
Robert Clipsham:
Why is this?
It's not a hard question. This code compiles:
class Foo {
const(Foo) myFoo() const {
return this;
}
}
void main() {
auto f = new Foo;
}
It's just in a const function the this is const, so if you want
28 matches
Mail list logo
