I have a short meta-programming approach for POD type safety from a previous question:
https://www.experts-exchange.com/questions/29056989/C-03-Templatize-Type-Enforcement-Program.html

I see the benefits of meta-programming as simplifying the development process for units - I believe that all new developers would have to do is to include a units header file, and follow a simple recipe for defining new data types.

I wrote in that question:
Other dimensional analysis areas that I am leaning towards:
 1. Make the class name part of the template
 2. Make the set of enumeration values part of the template so that they are not universally available
 3. Be able to operate on two different families of units. One obvious example would be:
        "distance (meters) = rate (meters/sec) * time (sec)".
     But we will have many other cross-unit operations as well.

I thought that I may as well see if I can get some tips on these ideas. If these 3 goals are realistic, but too much for one question, I am happy to work on what is reasonable for one question.

At the moment, I have to transcribe the previous question to my workstation, and then sell the ideas here and from the previous question to my lead software developer. The PM and Systems Engineer definitely like the idea of POD type safety. I just hope the lead likes the template approach.

I have a short program shown below that is also located in:
https://www.experts-exchange.com/questions/29056211/C-03-Type-Conversion-Errors-for-double-primitive-types.html#a42295035

I would like to templatize it to reduce the amount of tedium in handling multiple type conversions. I only show three types here (Hz, KHz, MHz), but I will be adding GHz as well. To make the classes easier to create, I got this good tip on the beginnings of templatizing the type enforcement/conversion classes:

What I would like to do is be able to handle the below program which has a bunch of friends and multiple implicit conversions for each type.

If I can get some meta-programming technique (or just plain templatizing) to generate lots of this type of code, I would greatly appreciate seeing how to do this. I'll be having to deal with many other families of types, such as distance: (feet, inches, millimeters, meters); time(seconds, hours - yes, I know about chrono); speed, etc.

#include <iostream>

class Hz
{
	friend class KHz;
	friend class MHz;
public:
	explicit Hz(double val) : val_(val) {}
	Hz(const KHz & khz);
	Hz(const MHz & mhz);
	double operator()() { return val_; }

private:
	double val_;
};

class KHz
{
	friend class Hz;
	friend class MHz;
public:
	explicit KHz(double val) : val_(val) {}
	KHz(const Hz & hz) : val_(hz.val_ / 1000.) {}
	KHz(const MHz & mhz);
	double operator()() { return val_; }

	KHz operator*(double mult)
	{
		return KHz(val_ * mult);
	}

private:
	

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…

Can someone help me write this program in c++?

 Suppose a teacher weights the four exams he gives 10%, 25%, 30%, and 35%.
Write a program that reads ten sets of four grades, prints the weighted average of each set, and prints the unweighted average of each test. The number of students should be in a global constant.

I know I need to use a for loop, but I'm not sure how to write it. Can someone show me how to code this along with guiding me through the code?

I am working on a project where I need to convert between units.
To avoid the Mars Landing mishap, I hoping to enforce enhanced typing of primitive types.
http://articles.latimes.com/1999/oct/01/news/mn-17288

For example, not all doubles representing length are meters; some are feet, or miles.
I don't want a function expecting meters to compile if it is given a double which is in feet.

The below program compiled in VS-2010 (C++03 required), but not in ideone.com
https://www.ideone.com/YGzOCy
(There is a chance that when I copied it incorrectly from VS 2010 to ideone.com.)
In the code below I have 3 comments indicating the problem areas I have.
Could you help me fix this program to address these 3 comments?

class Hz;
class KHz;


class KHz
{
public: KHz(double val) {val_ = val;}
	operator double() const {return val_;}
	KHz operator*(double mult) {return val_ * mult;}
	
private:
	double val_;
};


class Hz
{
public:
	Hz(double val) {val_ = val;}
	
private:
	double val_;
};


// 1. Would like to avoid this explicit conversion function:
Hz cnvKHzToHz(KHz khz) {return khz * 1000.0;}


void doSomething(KHz khz) {;}


int main()
{
	Hz ret = 0;
	KHz valkhz = 4.0;
	ret = cnvKHzToHz(3.0); // 2. Would like to have a compiler ERROR to prevent argument of double
	ret = cnvKHzToHz(valkhz);
	
	// doSomething(ret); // 3. ERROR: "Cannot convert parameter 1 from 'Hz" to 'KHz'
}

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Thanks in advance.
Paul

I would like help on drawing a grid within  rectangle when the checkbox "show grid" is true.
Can anyone help me on that?

I have a sample application written in C++ for a slap scanner. I am able to get the image scanned but do not know what to do with the data received. Can anybody guide me in the right direction?

I have attached the SaveImage Code from the sample app(Written in C++) and would like to know how convert it to vb.net. I am novice when it comes to C++.

I have tried to read the bytes from memory starting at the pointer returned to the tagImageData structure during the scanning process.

here is the structure that contains the image data:
    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> Public Structure tagImageData
        Public Buffer As IntPtr '< Pointer to image buffer
        Public Width As UInteger       '< Image horizontal size
        Public Height As UInteger      '< Image vertical size
        Public ResolutionX As Double  '< Horizontal image resolution (in PPI)
        Public ResolutionY As Double  '< Vertical image resolution (in PPI)
        Public FrameTime As Double    '< Image acquisition time (in seconds)
        '< This value contains the time taken for acquisition
        '< from device (excluding processing time).
        Public Pitch As Integer       '< Image line pitch (in Bytes).
        '  Positive values indicate top down line order,
        '  Negative values mean bottom up line order
        Public BitsPerPixel As Byte   '< Number of Bits per pixel
        Public Format As Integer      '< Image color format
       …

What technologies are best suited for the highest performance web services to handle the heaviest loads? Thousands (even millions) of transactions per second?

I know that Node.js can handle thousand(s) sessions on a single thread. And I do not know of any other technology which handle more than one session per thread. Am I right about that? Are there others that can do this also?

What about real-time programming as it relates to web-services. Is there such a thing?

And how about a few general words about hardware deployment? Having a central API call which distributes calls to hundreds of more specialized web servers? What about Caching for successive related calls?

And what about Machine Learning? Can algorithms be optimized by existing Machine Learning algorithms that reduce the average response times of the most heavily load web service?

Thanks.

Is it true that XslCompiledTransform is the solution?  Any examples?  I tried to use XslCompiledTransform in my c++ code but compiling failed. I don't know how to enable CRL in my VS 2002.  Please help.

I build a simpel program ,

but the button input need to wait 1000ms , for the next reaction
any way to fix that problem.

int led1 = 13;
int led2 = 12;
int button = 7;
int buttonState;

void setup() {
  
  
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(button, INPUT);

}

void loop() {

  buttonState = digitalRead(button);

  
if (buttonState == HIGH) 
{
digitalWrite(led2 , LOW);


} 
else
{

digitalWrite(led2,HIGH); 
  
}
  digitalWrite(led1, HIGH);  
  delay(1000);                      
  digitalWrite(led1, LOW);    
  delay(1000);                      
}

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Hello ,

Is there any library to trace / ping an ip or a better / faster way to get the ttl of an ip address ?

Hi guys.

I'm using this code to read a text file locally and do the word search as needed but the problem is that the file which this app will be reading will be online on a web server and the problem is that the code I have now to read this text online I don't seem to figure out how I can split data so that I can still do word search just like how I do to a local file. Here is the code I use to read local file:

while(!in.eof() && getline(in, line, ','))
							 {
								if((offset = line.find(ID, 0)) == string::npos)
								{
									id = atoi(line.c_str());
									in >> dat;
									getline(in, NUMBER, ',');
									getline(in, line, '\n');
									
									KEY = (int)atof(line.c_str());
									
									if(ID ==id)
									{
										ID = id;
										//dst = dvs;
										va = KEY;
										
									}

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Now this code part is the essential part of code as its what I want to be able to do in the following code which is the code that reads a file from the web.

    #include "stdafx.h"
    using namespace System;
    using namespace System::IO;
    using namespace System::Net;
    using namespace System::Text::RegularExpressions;
    int main(void)
    {
        Regex^ rxSubTitles = gcnew Regex("\\d.*>(?<subtitle>.*)<");
        String^ strFileIn = L"http://textfiles.com/adventure/221baker.txt";
        WebClient^ wc = gcnew WebClient();
        StreamReader^ fileWebIn = gcnew StreamReader(wc->OpenRead(strFileIn));
        String^ strData = "";
        while(!fileWebIn->EndOfStream)
        {
            strData = fileWebIn->ReadLine();
            if(rxSubTitles->IsMatch(strData))
            {
                // take ONLY the subtitle without additional decoration
                Console::WriteLine(rxSubTitles->Match(strData)->Groups["subtitle"]->Value->ToString());
            }
        }
        fileWebIn->Close();
        return 0;
    }

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This code simply gets all the Titles.

Here is my text file structure:

111,7643876,2
324,254935,
730,021738248,1

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As you can see each line has 3 data fields and

,

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is the data separator and as you can also see that the 3rd field can sometimes be empty. I think if you can look at the structure and also look at my first code even though I didn't post the complete code on the first code but I think that s the main part which you may need as its also the main part I'm having problem with when trying to apply it to the second code.

X = 1   2
       3   4

y = 3   1
       4   2
how can i convert x to y????

Hello ,


Any body knows a sample for re-calculate checksums and drop packets on netfilter module ?

Thank you