MVC 8.0
Windows XP
I would like to use multidimensiona l arrays in a function call. This
method works:
//-------------------------------------------------------------------------
void fun(double *d, int m, int n);
extern int main(void)
{
double a[2][3] = {1.0,2.0,3.0,4. 0,5.0,6.0};
double b[3][4] =
{1.0,2.0,3.0,4. 0,5.0,6.0,7.0,8 .0,9.0,10.0,11. 0,12.0};
fun( (double *) a, 2 ,3);
fun( (double *) b ,3, 4);
}
void fun(double *d, int m, int n)
{
// code here to work with d as an m x n matrix.
return;
}
//----------------------------------------------------------------------
But what I would really like to do is avoid the cast in the fun call
(mainly for readability and ease of programming). I.e., I would like
to change these lines:
fun((double *)a,2,3);
fun((double *)b,3,4);
into these lines:
fun(a,2,3);
fun(b,3,4);
and have the function interface be able to handle it. Is there a way
to set up the function interface to do this?
James Tursa 3 2000
>
>For the particular example above the simplest would probably be a templated function taking the matrix by reference,
template< size_t N, size_t M >
void fun( double (&d)[N][M] ) { ... }
Thanks. I will look into this formulation.
>But if you're going to matrices and are confounded by this problem, I suggest you use some ready-made matrix library.
Thought of this, but not really a good option for me. The function I
am writing will serve as an interface from some existing code to other
routines. I don't have control over how this existing code is written.
I just want to set up a simple interace for the other programmers to
use. Thanks again.
James Tursa
>
>For the particular example above the simplest would probably be a templated function taking the matrix by reference,
template< size_t N, size_t M >
void fun( double (&d)[N][M] ) { ... }
Great suggestion. It is *almost* doing exactly what I want. The
problem I am having now is the code as written can't tell when I am
trying to call the scalar routine and when I am trying to call the
1-dim routine. Is there a way to fix this, short of renaming the
scalar routine? Code is as follows:
James Tursa
#include <stddef.h>
void fun(double *c);
template <size_t m>
void fun(double (&c)[m])
{
// 1-dim code to fill in values of a double array of size m
}
template <size_t m, size_t n>
void fun(double (&c)[m][n])
{
// 2-dim code to fill in values of a double array of size m x n
}
int main()
{
double a;
double b[3];
double c[2][3];
fun(&a); // this one calls the scalar routine
fun(b); // this one also calls the scalar routine. Want it to
call the 1 dimension routine
fun(c); // this one calls the 2 dimension routine
}
void fun(double *c)
{
// scalar code to fill in value of a double scalar
}
>
>For the practical problem, simply change
void fun(double* c)
to
void fun(double& c)
and change the call accordingly, from fun(&a) to fun(a).
Cheers, & hth.,
- Alf
Super! Works just like I want. Thanks!
James Tursa This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: Web Developer |
last post by:
Hi,
Comming from Java, it seems that prototype declarations are like abstract
methods. I have not read classes in C++ yet, but prototype declarations are
a strange concept. Any comments appreciated.
WD
|
by: Elf M. Sternberg |
last post by:
One of the complaints about prototype.js (google for it if you're not
familiar with it) is that it's poorly documented. I have this inkling
that the key to understanding prototype.js is in the bind function.
The problem with Javascript is that the "this" operator is poorly
overloaded and it is often hard to understand in the context of
object-oriented javascript
So, let's start with the definition:
|
by: stephane |
last post by:
Hi all,
What I am trying to achieve is an 'inherits' method similar to Douglas
Crockford's (http://www.crockford.com/javascript/inheritance.html) but
that can enable access to the superclass' priviledged methods also. Do
you know if this is possible ?
In the following example, I create an ObjectA (variable a), an ObjectB
which inherits ObjectA (variable b) and an ObjectC which inherits
ObjectA (variable c1). The 'toString ()' method...
|
by: Rob Somers |
last post by:
Hey people,
I read a good thread on here regarding the reason why we use function
prototypes, and it answered most of my questions, but I wanted to
double check on a couple of things, as I am writing something up on
functions, and I don't like writing about things I am not sure about.
Ok, then, here we go:
I initially thought that one would only really need to use a function
|
by: Z D |
last post by:
Hello,
I'm having a strange problem that is probably due to my lack of
understanding of how threading & COM Interop works in a WinForms.NET
application.
Here's the situation:
I have a 3rd party COM component that takes about 5 seconds to run one of
its functions (Network IO bound call). Since I dont want my GUI to freeze
| |
by: Steve-O |
last post by:
The following code works great in FireFox, Opera, Netscape, Safari, and
Gecko, but NOT IE. Why?
I tried using 'native' js with setInterval and setTimeout, but I get
the same result. My IE security settings are not an issue.
Anyone have any insight on this?
Thanks!
-sh
|
by: mmcloughlin |
last post by:
I'm learning about objects and am trying to figure out how basic
inheritance works. I've got into the habit of explicitly setting the
prototype object with an object literal as it seems to make the
creation of a class easier to read/understand.
Anyway it seems to break the inheritance chain in the following code
and I don't know why.
window.onload = function() {
|
by: ThinkRS232 |
last post by:
I have a PocketPC .Net application (Compact Framework) that calls a Win32
DLL. This DLL in turn has a WINAPI type callback. Following is the actual
prototype.
Win32 DLL Function Prototype
-----------
Status = XferFiles(int PortID, int Direction, int Protocol, LPCTSTR Fspec,
int Flag, int (WINAPI *Callback)(int Chgflg, char *Fname, long Bytcnt, int
Curblk, int Errcnt, unsigned Rate));
|
by: beseecher |
last post by:
Hi,
In my research in the javascript language I have encountered problems
with implementing prototype inheritance while preserving private
methods
functioning properly. Here is an example:
function A(){
var _this = this;
this.a = 10;
|
by: liketofindoutwhy |
last post by:
I am learning more and more Prototype and Script.aculo.us and got the
Bungee book... and wonder if I should get some books on jQuery (jQuery
in Action, and Learning jQuery) and start learning about it too?
Once I saw a website comparing Prototype to Java and jQuery to Ruby...
but now that I read more and more about Prototype, it is said that
Prototype actually came from Ruby on Rails development and the creator
of Prototype created it...
|
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
| |
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
|
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
| |
by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
|
by: bsmnconsultancy |
last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...
| |