Why a generic code have to be ugly?
At this age of compilers and languages, and the capabilities of DMD?
Why that many casts? or implicit casts?
DMD already doing it behind the scenes with constant folding,
not sure but i think literals stay that way mostly because of C
compatibility!
Thanks.
so Wrote:
> Basically what i am asking is hmmm, ability to write generic constants? :)
>
> Thanks!
Hi,
When writing generic FP code i always use real literals and cast to T, or int.
I suggest doing this.
Like:
T exp3(T)(T x)
{
if (x < cast(T)(-1.15365L))
{
retu
I can't think of any solution they might provide sorry.
You know there are C++ equivalents, for years and they didn't solve any
problems above.
Maybe i can use them to disable implicit casting, but then again program
won't compile. :P
Thanks!
On Sun, 28 Mar 2010 18:09:21 +0400, biozic wrot
Le 28/03/10 10:57, so a écrit :
Well, i am having hard time explaining, it is not a surprise that you
don't understand.
To make things clearer, lets forget floats for a seconds and change your
code to standard unsigned types.
import std.stdio: writeln;
struct Vector(T) {
this(T m) { mm = m; }
You didn't change anything there, just back to original code, now just
enabled implicit cast again!
Please read my next replies, everything should be clear now. :)
Thanks!
On Sun, 28 Mar 2010 14:32:21 +0400, bearophile
wrote:
so:
Well, i am having hard time explaining, it is not a surp
so:
> Well, i am having hard time explaining, it is not a surprise that you
> don't understand.
I think I have understood you this time. Writing skills are important for a
programmer :-)
Is this what you are asking for? But it's not very good code:
import std.stdio: writeln;
struct Vector(T)
Everything comes to this...
Why "3" is an int?
Why "0.3 is a double?
I guess these constraints was there before generic coding comes out, and
we are just stuck with it!
If these sound so naive, sorry about it, I don't know compiler/language
history.
Thanks!
On Sun, 28 Mar 2010 12:29:17 +04
Basically what i am asking is hmmm, ability to write generic constants? :)
Thanks!
On Sun, 28 Mar 2010 12:29:17 +0400, bearophile
wrote:
so:
With one exception yes, i want all 3 test pass with your fix to implicit
cast.
You know, we are trying to write generic code.
I don't understand
Well, i am having hard time explaining, it is not a surprise that you
don't understand.
To make things clearer, lets forget floats for a seconds and change your
code to standard unsigned types.
import std.stdio: writeln;
struct Vector(T) {
this(T m) { mm = m; }
Vector opBinary(strin
so:
> With one exception yes, i want all 3 test pass with your fix to implicit
> cast.
> You know, we are trying to write generic code.
I don't understand your problem/needs, sorry.
Bye,
bearophile
With one exception yes, i want all 3 test pass with your fix to implicit
cast.
You know, we are trying to write generic code.
Thanks!
On Sat, 27 Mar 2010 22:21:46 +0200, bearophile
wrote:
Are you trying to do this?
import std.stdio: writeln;
struct Vector(T) {
this(T m) { mm = m; }
so:
> With this in mind, just one thing bugs me.
>
>
> import std.stdio;
>
> struct vector(T) {
> this(T m) { mm = m; }
> vector!T opBinary(string s)(T m) if(s=="*") {
> return vector!T(mm * m);
> }
> T mm;
> }
>
> void test(T)() {
> vector!T v =
Le 27/03/10 18:18, so a écrit :
With this in mind, just one thing bugs me.
import std.stdio;
struct vector(T) {
this(T m) { mm = m; }
vector!T opBinary(string s)(T m) if(s=="*") {
return vector!T(mm * m);
}
T mm;
}
void test(T)() {
vector!T v = vector!T(0.5);
vector!T u = v * 0.3;
writeln
Oh... wait a second.
In http://www.digitalmars.com/d/2.0/float.html :
"Regardless of the type of the operands, floating point constant folding
is done in real or greater precision. It is always done following IEEE 754
rules and round-to-nearest is used.
Floating point constants are internal
I think you would end up creating a scalar class/struct with operator
overloading to get the behavior you are looking for. I realize that is
more overhead than what you would want but I don't see another way.
so wrote:
> In C++!
>
> I have a type defined in the core library like..
> typedef float
so:
> When i have the code :
> scalar m = 0.5fp;
>
> I want compiler to implicitly cast it to typeof(scalar).
> so when the scalar is float, m will be 0.5f.
I am starting to understand, sorry if I am a dumb bear :-) Programming in C++/D
is usually much less hard than understanding humans.
I thin
On Sat, 27 Mar 2010 15:54:19 +0200, Bill Baxter wrote:
Note that 'real' is a built in type in D. It's an 80-bit float on x86
procs and 64-bit elsewhere.
So .5L is like cast(real).5. Not the solution you were looking for.
--bb
That "r for real!" was joke.
What i mean is a literal/template/p
On Sat, 27 Mar 2010 12:20:38 +0200, so wrote:
I haven't seen a single C++ library able to do this properly. (I would
just copy it!)
This is one of the reasons why something like
std::numeric_limits::function() exists.
Which makes a generic and *clean* numeric code in C++ nonexistent.
Don!
Note that 'real' is a built in type in D. It's an 80-bit float on x86
procs and 64-bit elsewhere.
So .5L is like cast(real).5. Not the solution you were looking for.
--bb
2010/3/27 so :
> On Sat, 27 Mar 2010 15:28:22 +0200, bearophile
> wrote:
>
>> so:
>>>
>>> One thing i can think of now is a
On Sat, 27 Mar 2010 15:28:22 +0200, bearophile
wrote:
so:
One thing i can think of now is adding another float literal, maybe 'r',
for "real"!,
See here, Unfortunately it's called "L" not "r":
http://www.digitalmars.com/d/2.0/lex.html
FloatSuffix:
f
F
RealSuffix:
so:
> One thing i can think of now is adding another float literal, maybe 'r',
> for "real"!,
See here, Unfortunately it's called "L" not "r":
http://www.digitalmars.com/d/2.0/lex.html
FloatSuffix:
f
F
RealSuffix:
L
bearophile
On Sat, 27 Mar 2010 13:52:28 +0200, bearophile
wrote:
Can you explain better what the problem is and what kind of solution you
would like?
Bye,
bearophile
One thing i can think of now is adding another float literal, maybe 'r',
for "real"!,
Which means you are free to cast this to any
On Sat, 27 Mar 2010 13:32:24 +0200, Robert Clipsham
wrote:
On 27/03/10 10:20, so wrote:
In C++!
I have a type defined in the core library like..
typedef float scalar;
//typedef double scalar; // <-- whole framework is now double precision
alias float scalar;
//alias double scalar;
Next
On Sat, 27 Mar 2010 13:52:28 +0200, bearophile
wrote:
so:
Since D is superb, i like to know how you do it in D.
If you got a better idea in C++, i would like to hear that too!
You know there are float literal too, in C++/D, like: 5.5f
I don't think D can help you more than C++ here.
Can yo
so:
> Since D is superb, i like to know how you do it in D.
> If you got a better idea in C++, i would like to hear that too!
You know there are float literal too, in C++/D, like: 5.5f
I don't think D can help you more than C++ here.
Can you explain better what the problem is and what kind of solu
On 27/03/10 10:20, so wrote:
In C++!
I have a type defined in the core library like..
typedef float scalar;
//typedef double scalar; // <-- whole framework is now double precision
alias float scalar;
//alias double scalar;
Next i instantiate vectors, matrices etc... from templates.
typedef
In C++!
I have a type defined in the core library like..
typedef float scalar;
//typedef double scalar; // <-- whole framework is now double precision
Next i instantiate vectors, matrices etc... from templates.
typedef vector_t vector;
typedef matrix_t matrix;
Until now everything cool, here pa
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