C# :: Define Optional One To Many Relationship?

Apr 15, 2015

If I’m trying to define an optional one to many relationship I need to reference the primary key of the table

e.g

modelBuilder.Entity<TCC_ArchivedIntegrationExceptions>()
.HasRequired(t => t.TCC_TransactionHistory)
.WithOptional(t => t.TCC_ArchivedIntegrationExceptions);

Where TCC_ArchivedIntegrationException is the optional key.. but those models are inheriting their key from a base entity

So do I have to create the key explicitly in the model or is there another way around this?

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C++ :: Optional Parameter In String Stream

Sep 2, 2013

I'm reading in a data set using an ifstream, then fetching line by line to a stringstream:

std::ifstream sfile(filename);
std::string test;
std::getline(sfile, test);
std::stringstream sline(test);

(I'm not sure why I used an intermediate string; it's pretty much legacy-code at this point, which I just reuse every time. Still works, so why change it!)

The problem is I'm using two types of data sets now, and the difference is one (optional). Most data files just have an arbitrarily large number if the second must be ignored, but others have nothing.

In the normal case, I'd simply use sline >> d >> L; to extract the parameter values. However, I'm not sure how this line will behave if the second parameter is omitted. Will it read nonsense? How do I check whether or not the parameter was set or not?

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C++ :: Optional / Default Parameters In Class Functions?

Aug 19, 2014

In the thread "Making a argument optional to function", it is stated that to set default values for arguments of a function you can simply do so in the function definition, like:

int myfunc(int a, int b, int c=3) {...}

This then automatically puts c to 3 in the function body if a call like myfunc(1,2); is made, if I understood correctly. However, this does not seem to hold for class functions. For example, something like:

class classy {
public:
int class_func(int, int, int); // class function prototype
}
int classy::class_func(int a, int b, int c=3) {...}

fails to compile. What I would like is to be able to call class_func outside of this class (by including it as a header in another macro), optionally specifying c. If c is not specified in the call, it should use a default value.

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C++ :: Difference Between HAS-A And IS-A Relationship?

Mar 20, 2014

What is the difference between HAS-A and IS-A relationship?

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Visual C++ :: Relationship Between Two Hex Strings?

Aug 19, 2013

I'm trying to make an application for ELM327 trouble code scanning device for my own educational purpose. Most of my app code is done. however, I am stuck at one point. And I need finding relationship between two hex strings.

I have logged some communication between ECU and a chinese code scanning device for carrying out car's fuel pressure test. However there is one message (that is sent from the user side) that keeps on changing each time which is dependent upon the last message received from the ECU which is also varying every time.

Code:
RECEIVED (07E8) SEND (07E0)
05 67 03 0C 17 6A 00 00 05 27 04 8F 45 37 00 00
05 67 03 0C DB 68 00 00 05 27 04 B0 70 6B 00 00
05 67 03 10 3B 87 00 00 05 27 04 3B BC 10 00 00

[code]....

as it can be seen 3 bytes are always changing with each test, both, in the message received from the ECU, and the one sent back to the ECU from the diagnostic scanner. Trying to figure out relationship between these two strings?

P.S: about 16 million combinations for 3 byte data are possible... there must be some link between them...

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C/C++ :: Two Numbers Relationship Program Error

Aug 15, 2014

I write below two numbers relationship program and got below error.

//two numbers relationship
//take standard and console input and output
#include <stdio.h>
#include <conio.h>
//take function main
main()

//define numbers {
int num1; //first number
int num2; //second number

[Code] ....

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C :: Pointing To Define To Get Value

Jul 24, 2013

I am trying to understand how to get the following value from a define. The code i am trying to understand is as follows:

Code:
#define RADIO_CONFIGURATION_DATA_RADIO_DELAY_CNT_AFTER_RESET {0xF000}

Code:
#define RADIO_CONFIGURATION_DATA {
Radio_Configuration_Data_Array,
RADIO_CONFIGURATION_DATA_CHANNEL_NUMBER,
RADIO_CONFIGURATION_DATA_RADIO_PACKET_LENGTH,
RADIO_CONFIGURATION_DATA_RADIO_STATE_AFTER_POWER_UP,
RADIO_CONFIGURATION_DATA_RADIO_DELAY_CNT_AFTER_RESET,
RADIO_CONFIGURATION_DATA_CUSTOM_PAYLOAD
}

and also have this

Code:
typedef struct {
U8 *Radio_ConfigurationArray;
U8 Radio_ChannelNumber;
U8 Radio_PacketLength;
U8 Radio_State_After_Power_Up;
U16 Radio_Delay_Cnt_After_Reset;
U8 Radio_CustomPayload[RADIO_MAX_PACKET_LENGTH];
}

tRadioConfiguration;

so then in the api i have the following

Code:
for (; wDelay < pRadioConfiguration->Radio_Delay_Cnt_After_Reset; wDelay++); .

so my question is how do i declare my variables, correct terminology ?, to achieve this.

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C :: Possible To Define Arrays

Mar 6, 2015

I have one small doubt in arrays. Is it possible to define arrays like this a[b[10]] ?...

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C++ :: Define Variable That Is In HEX Value

Aug 31, 2013

I want to define variable that is in HEX value & has 64 bits.but I dont know what I can use.....I use unsigned long long but it doesn't useful.

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C :: How To Define The Lock Detect

Feb 24, 2013

It is my first time in use lock detect so i didn't now how to start.

how to define the lock detect?

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C :: How To Define Negative Number

Sep 3, 2014

I nead to define an a negative number a normal posetive number i defined like #define RSSI_UP 1 can i write #define RSSI_DOWN -1???

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C++ :: Define A Vector In A Class?

Aug 9, 2013

First this is my code:

#include <iostream>
#include <vector>
#include <cstdlib>

[Code].....

the blacked content got problems: the error messages are the throat_t::P or throat_t::T is inaccessible.

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C++ :: How To Define A Class Which Have Two Members

Sep 16, 2013

I want to define a class, which will have two members, for example, vaporPressureStatus and vaporPressure

enum vpStatus_t {nonesense, unknown, known, saturated};
class pore_t {
public:
vpStatus_t vpStatus;
double vaporPressure;
};

when vpStatus is nonsense and unknown, the vaporPressure should not have a value; and if I calculate out a value for vaporPressure, the vpStatus can be set as known.

I am wondering if there is any set, pair or other structure can hold this two members together, so that when I change one's value, the other guy will also change accordingly.

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C++ :: Define A Class For A Type

Apr 29, 2014

Define a class for a type called CounterType. An object of this type is used to count things, so it records a count that is a non-negative whole number.

Include a mutator function that sets the counter to a count given as an argument. Include member functions to increase the count by one and to decrease the count by one. Be sure that no member function allows the value of the counter to become negative.Also, include a member function that returns the current count value and one that outputs the count. Embed your class definition in a test program and run sufficient tests to verify it all works correctly.

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C++ :: Using Structs To Define A Function

Sep 27, 2013

What I'm trying to do :

struct foo {int x; int y;};
foo function_example(int x, int y) {
foo temp;
temp.x = x;
temp.y = y;
return temp;
}

Works as is, however when I try doing it through seperate class files :

//header file for class example_class
struct foo {int x; int y;};
foo function_example(int x, int y);

//source file for example_class
foo example_class::function_example(int x, int y) {
foo temp;
temp.x = x;
temp.y = y;
return temp;
}

I get an error telling me that foo is undefined, and that declaration of function_example(int x, int y) is incompatible with the declaration of it in the header file.

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C++ :: Define Long Variable And XOR

Aug 15, 2013

I want to write encryption algorithm.first af all I need to define variable( binary input ) that it is 256 bit but I dont know what should I use...then I want to XOR this to variable ( a & b ) ( each of them is 256 bit)

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C++ :: How To Define Own Header File

Jan 16, 2013

I have written code for a timer. with everything and i want to include this so i dont need to write or copy the reqd code each time. how do i do this?

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C# :: How To Define Objects Within Classes

Oct 7, 2014

When are you creating fields/properties for specific classes and when you are not doing it but creating them inside just lets say straightaway inside some methods within that classes. I mean if i got class where inside i want to create instance of some other class and then pass this instance to another class - should i create a field for it within class i am doing this operation or not? I was always reading that you create field/properties when its belong to class itself. So if i want only to create some instance outside class i am working and pass it to other class and this is not exactly the part of this class shouldnt i create a field for it and just create it inside method?

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Visual C++ :: How To Define A Hash Map

May 15, 2014

I want a speed of O(1) in search, insertion and deletion.

is std::map<> the way to go?

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C++ :: Create User Define Literal?

Jul 14, 2014

In C++ there are a number of primitives that are not defined in terms of other types. By this I'm thinking

int a = 1;
char b = 'M';
float c = 3.45f;
short d = 0xC3A3;

Is it possible to define your own literal? What I would like to do is have a hex literal for a data type where n = sizeof(data_type). If this type were a big integer, then I would want something like:

BigInt e = 0x13CA9B0C98D983E912DA0B0A9F87E0;

My goal is to assign a value from one contingous chunk of bytes and to not do it with a string.

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C++ :: Proper Way To Define A Variable Type

Sep 17, 2013

I just compiled some code I've been working on at a different OS/compiler and realised that Code: sizeof(unsigned long) returns 4 in one pc and 8 in another.

I've heard that bytesize conventions for basic variables were not particularly "universal" before but this is the 1st time I've had a problem with it.

how do I make a typedef that clearly indicates to whatever compiler compiler I want u32 to be an 32bits unsigned and u64 to be 64bits?

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C :: Define Array Type With 4 Elements?

Jan 18, 2015

How can I define type MARKS which will be able to hold 4 elements just like array? I want to access it just like normal array elements using brackets []. In the following struct I want to use such type.

Code:

typedef struct {
MARKS ** pointers;
} ARGUMENTS
void main(){
ARGUMENTS arguments;

[Code] ......

Purpose of the struct ARGUMENTS is to hold 4 pointers to string. I want to mark few positions in string so I can simple access them. E.g. name=John

Code:
arguments[0][0]=0; // begin of the param name
arguments[0][1]=3; // end of the param name
arguments[0][2]=5; // begin of the value
arguments[0][3]=8; // end of the value I mean not to save int but the pointer to the corresponding position.

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C++ :: Where To Define A Large Number Of Objects

Jan 20, 2013

I am trying to run a simulation with a large number of objects (mainly arrays and vectors). I am not sure where shall I define my objects: inside or outside of the main() function, like the following two structures:

(1) ---------------

//main.cpp
int main(){
array<double, 1000> a_1 = {};
array<double, 1000> a_2 = {};
......
func_1(a_1, a_2, ..., a_100);
return 0;
}

[Code]...

I know there is a question about scope. But besides this question (which seems have no difference between these two structures here), is there any difference in terms of execution performance or security issue?

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C++ :: Vulnerable Recursive Programming On Define

May 20, 2013

I've been studying "algorithm" by myself by book. And there's this part - vulnerable point of "define" syntax on recursive programming.

Code:

int max_arr2(int arr[], int arr_len) {
int (arr_len == 1)
return arr[0];
else
return max(arr[arr_len-1], max_arr2(arr, arr_len-1);
.
.

This book says, " function 'max_arr2' is just recursive function, without any problem. but if max() is defined like this,

#define max(x,y) ((x)>(y) ? (x):(y))

and if array is just declined, it will take very long time."

I typed this code and run, and actually it really takes long time.

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C++ :: Possible To Define And Write Own File Extension

Jan 16, 2013

Is it possible to define and write your own file extension. if so is it an easy process or a complex waste of time. All I want to do is define a source file for a programming language I write.

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C++ :: Define To Overload Virtual Function

Jul 11, 2014

I want to overload pure virtual function from 3rd party SDK class to put my debug messages like that:

errorStatus aXsaction(){printf(_T("
abort transaction"));transactionManager->abortTransaction();}

#define transactionManager->abortTransaction() aXsaction()

But compiler complains on the minus sign:
error C2008: '-' : unexpected in macro definition

Is it possible to trick the compiler?

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