I would like to avoid throwing things in constructors as much as possible.
Is this good design to have a static class method that checks arguments the caller will give to the constructor. The documentation of the class will say, thou shall call this method to validate thine arguments before calling the constructor, or else segfault may befall thoust.
I've been trying for more than one month to access a method found in a library called libcocosnas_static.a. I'm using Cocos2d-X version 2.0.4. The library has been used many times by my company to make games using cocos2d-1.0.1-x-0.12.0 without any problem.
This is what I've done:
1- I added the include paths of the library to both eclipse and Android.mk
2- Included the .h file using #include "NASPlatformUtil.h"
3- Added the libcocosnas_static.a file to the proj.androidobjlocalarmeabi folder
4- Added "LOCAL_WHOLE_STATIC_LIBRARIES += cocosnas_static" to the Android.mk file
5- Called the function using: NASPlatformUtil:: openUrl("http://xxx.xxx.com/");
I can right click on the function, click Open Declaration and get it without any problem, but the compiler keeps on giving me that dreaded error...
Have following code:
class Program
{
static void Main(string[] args)
{
[Code]....
My question according to what i just wrote:
1. Is that mean that Do() is only available for use by Dog itself because Dog is 'oryginal' Dog, and if i create new dogs - instances of oryginal Dog (dog1, dog2 ...) they cant access because Do is only available fo 'oryginal' one? Is that correct thinking?
2. If i would want to have something common (e.g value) for all dogs is that good way to create static field/method for Dog instead of non-static once then all instances of Dog would access Dog static member to get/change it? Just stupid example: static method GetAmountOfLegs() which return 4 Then all instances can take/call that value from Dog. Is that correct thinking?
VS 2012 / Windows 7 64 bit
class
class myclass {
public:
myclass(){/*stuff here*/}
myclass(int* p) {MyPointer = p; myclass()}
[Code] ....
it works until the myclass(int* p) calls myclass()
then the MyPointer will become CCCCCCCC (NULL value)!
is there a way to stop the second constructor from resetting the pointer value to null?
Allow users to enter their name and favorite saying in a single method that gets invoked two times. If I can only return one value at a time, how am I suppose to get name and favorite saying out of UserInput()?
static void Main(string[] args) {
string displayName, favoriteSaying;
DisplayInstructions();
Console.WriteLine();//readability
[Code] ....
what is static method?
why we can use static method inc#?
Im trying to create a map container with the key being an ID number and the value being a pointer to a class object. Currently Im creating objects and storing their address in the container. I am getting a runtime error when calling the virtual method with this pointer. I believe that the problem is being called because they aren't being called pointer/reference. let me know if you need more.
if(command == 'F'){
inputDataFile>>name>>mNumber>>email>>department>>tenure;
faculty newFaculty(name,mNumber,email,department,tenure);
person* facultyAdd = &newFaculty;
cout<<"Note: Adding "<<mNumber<<"..."<<endl<<"Adding ";
people.insert(pair<string,person*>(mNumber,facultyAdd));
[Code]...
how the operator overloaded methods called in C++?
Class String {
int len;
char *str;
public:
String(const char *str1="") {
len=strlen(str1);
str=new char[len+1];
strncpy(str,str1,len+1);
[code]....
How to use static in a class, function and variable.
View 1 Replies View RelatedI declared a member method to a class in its header file and implemented it in the cpp file. When I build and run the project in XCode, everything works fine. When I try to do it with a makefile, I get undefined symbols linker errors.
parser.h
Code:
#ifndef ENGINE_SCRIPT_PARSER_H
#define ENGINE_SCRIPT_PARSER_H
#include <string>
#include "variable.h"
namespace ninja_game_engine {
[Code] ....
The exact makefile looks like this:
Code:
test:
g++
Code/Engine/Modules/Timer/timer.cpp
Code/Engine/Modules/list.cpp
[Code] ....
I'm pretty sure that there is a weird namespace gotcha that I'm unaware of that LLVM (default OSX compiler) is compensating for that g++ isn't. Or maybe something weird with the optimization? I want the tests running at that level to make sure everything that is volatile is declared as such.
Rest of the code located here: [URL] ....
I'm still working on my process API, as in my previous posts. Right now I'm trying get my class portable so I can use it for any language/compiler by using a factory design pattern. I'm having problems figuring out how to call the methods properly from my interface pointer in my factory class without causing a segmentation fault.
Code: main.cpp
Code: #include "exports.h"
#include <iostream>
using namespace std;
[Code]......
I have a COM Object created using ATL (without MFC Support)
The Object has 1 method that opens a Dialog (that does all the rest) and when finish - returns 2 values back (1 is enough)
Currently I call it from another EXE:
hr = CoCreateInstance(
CLSID_MyControl,
NULL,
CLSCTX_INPROC_SERVER,
IID_IMyControl,
(void**) &pMyControl
);
and then:
hr = pMyControl->MyMethod (ATL::CComBSTR(InputString1), ATL::CComBSTR(InputString2), &IntReturned, &IntReturned);
Is it possible to call it as is from a browser ?
How can I Instantiate the object and invoke my method (with params) from the browser ?
will it open the dialog ?
When the below is done, does it call the constroctor only, and if yes, constructors do not have return types so how does it work? is there anything behind the scene?
wxAddHandler(new wxPNG_HANDLER);
and
sf::RenderWindow(sf::VideoMode(...),...);
Say I have a function pointer with this definition:
void ( *pressFunc ) ( void*, void* );
And i did this function:
void functionWithOneArg ( void* testPtr );
And i did this
pressFunc = &functionWithOneArg;
One. Would C actually let me do this? ( Assigning a function with one argument to a function with two )
Two. If so, what would happen to the second argument that is passed the function when its called? Does it just get 'cut off' and only the first argument is passed?
I am creating class to be call only once in time so i am trying to implement it static to access it once i created static constructor which will be implemented within first instance of the class. My target is to pass two parameters to onstructor but as i said class should be call only once anyhow i am able to create many instances of that class which i would like to avoid and dont know how firstl i tried to create only one constructor as static with parameters but its not allow then i created static constructor and public contructor which takes two parameters but in this case i am able to create many instances:
public class HeartbeatSupervisor : ICheck
{
private Server _server;
private Protocol _protocol;
/// <summary>
/// HeartbeatSupervisor dd = new HeartbeatSupervisor();
/// </summary>
///
static int k = 0;
static HeartbeatSupervisor()
{
[code]....
inside Program Main i am able multi instances...
HeartbeatSupervisor dd = new HeartbeatSupervisor(new Server(), new Protocol());
HeartbeatSupervisor ee = new HeartbeatSupervisor(new Server(), new Protocol());
I have function that returns historical data. I can access it, using file name. If I use file name, it reads that file and saves it to dictionary, so that in the future, if historical data is required for the same file, it does not read it again (it's lazy loading). If no file is supplied to the function, it tries to read file which is given in app settings.
However, for unit testing, I do not want to read any file. Instead, I want it to use small sample of hardcoded historical data. In order to do that, I think, I need to introduce interface to it. Then I can use some IoC to choose between different implementation for unit testing purpose and ordinary launch of application.
Function to get history is given as follows:
public static class Auxiliary
{
private static Dictionary<string, MyData> _myData;
public static MyData GetData(string fileName = null)
{
// ...
}
}
I have created default Unit Test project with Visual Studio so, as far as I know, by default it uses MSTest as test runner and MSUnit as unit testing framework but it does not have any IoC container so I should manage NuGet packages for solution and install Unity.
As far as I know, MSUnit (aka Moles) can unit test static methods (it's unconstrained isolation framework, like Typemock Isolator, unlike NUnit) but still many people suggest not to use any static methods for unit testing.
Should I use shim or stub [URL] Stubs should be used for faking external dependencies and here it is not external library, but my own code.
class IFoo {
virtual void Bar() = 0;
};
class FooAbstract {
virtual void Bar() {}
[Code] .....
How to call the Bar() method from FooTemplate in FooDerived::Bar()?
I need to create a method (constructor) to initialize a bigint to an int value you provide [0, maxint].
Example: bigint(128).
Here is my class:
#ifndef BIGINT_H
#define BIGINT_H
const int MAXINT = 500;
class bigint{
public:
bigint();
[Code] ....
So if the user inputs (4123 for example). How would I make 4 in size[0], 1 in size [1], 2 in size [2], etc. I don't even know where to start. Im guessing I would start with a for loop. It has to be an integer. I cant use a string yet.
In C you can just load and call the address of a function without defining its arguments like this:
Code: int (__stdcall *pMessageBox)();
int main() {
HMODULE h=0;
h = LoadLibrary("user32.dll");
pMessageBox = GetProcAddress(h, "MessageBoxA");
// MessageBoxA
pMessageBox(0, "MessageBoxA has been called!", "MessageBox Example", MB_OK);
return 0;
}
In C++ the same code gives "too many arguments for call" error unless you define the function first with its parameters.
Is there a way to do it the same way in C++?
There are, or course, better ways to do this, but I need to stick to some rules:
(1) Use only pointer variables and not arrays or structs.
(2) Use the three functions shown--regardless of easier methods.
The program should ask for some input, operate on those numbers, and then display the results. I know I am confused over these things:
(1) All that syntax using '*' and '&' or neither.
(2) How to use the char type correctly.
(3) How to use a char type input as an operator (a + b).
(4) How to use the pointer of the operator variable (+,-,*,/) in an actual equation.
Code:
#include <stdio.h>
#include <stdlib.h>
// *** Prototype Functions ***
void Post_Results (float*);
void Calculate (float*, float*, char*, float*);
void Get_Numbers (float*, char*, float*);
[Code]......
I have a class that extends another class, and I want multiple constructors in the child class, but the child constructor needs to call the parent constructor. This is what I have
In the child class:
ChildClass::ChildClass() {
ChildClass(1);
}
ChildClass::ChildClass(int i)
: ParentClass(i) {
// do stuff
}
In the parent class:
ParentClass::ParentClass(int i) {
// do stuff
}
In my main program:
ChildClass child1;
// do stuff with child1
// breaks
ChildClass child2(1);
// do stuff with child2
// works fine
Using the default constructor breaks my program at runtime, but using the one with a parameter works fine. The default constructor calls the other with the same thing as the main part in the program, so I would think this should make no difference, but obviously that isn't the case.
I am having trouble creating a new User from my User Class. The error I am recieving:
Error3'HospitalSystemBL.User' does not contain a constructor that takes 2 argumentsC:UsersStudentdocumentsvisual studio 2010ProjectsHospitalSystemHospitalSystemLogin.aspx.cs2131HospitalSystem
In my User class, I have two constructors. Default and an overloaded constructor.
//default constructor
public User() {
}
//overloaded
public User(long UserName, string Password)
[Code] ....
I am trying to create my user in my Login class. Why is the error saying "does not contain a constructor that takes 2 arguments" when I have a constructor (above), User passing two arguments: UserName and Password? Here is my code for the login:
protected void btnLogin_Click(object sender, EventArgs e) {
try {
int Userid = Convert.ToInt32(txtUser.Text);
string password = txtPassword.Text;
[Code] ....
I am doing fixed point implementation in c++ which is done by the following code
#ifndef __fixed_point_header_h__
#define __fixed_point_header_h__
#include <boost/assert.hpp>
#include <boost/static_assert.hpp>
#include <boost/operators.hpp>
#include <limits>
[Code] ....
I am getting the error ambiguous overload for âoperator<â in âbeta < ((-5.0e-1) * pi)â
I know the problem the static member function cannot access the members and objects of structs. am i right?
and how to solve this problem, do i need to implement the cossin_cordic function as a non member function.
Can people just do a quick sanity check of this concept?
I'm playing around with a technique to parameterise a template with the largest 'sizeof' result for a set of classes.
A, B, C & D are classes with 1, 2, 3 & 4 members respectively.
e is an instance of E, who's array member is sized according to the largest size of A, B, C or D.
Code:
// MaxSizeOf for four parameters.
template <const size_t S1,
const size_t S2,
const size_t S3 = 0,
const size_t S4 = 0>
struct MaxSizeOf
[code].....
// Program to calculate fine using class.
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<string.h>
class library {
long bookid;
char bookname[25];
[Code] ....
In the above program, how do I call the diff. constructors in main?
I've written an Array class to create 1d,2d and 3d array and it works fine for every test : example of the constructor of the array class for 2d case:
Array::Array( int xSize, int ySize ) {
xSize_ = xSize;
ySize_ = ySize;
zSize_ = 1;
vec.resize(xSize*ySize);
}
It works fine , but when i need to use this constructor inside of other constructor, i get the "no matching function error" ,
part of my code:
class StaggeredGrid {
public:
StaggeredGrid ( int xSize1, int ySize1, real dx, real dy ) : p_ (2,2) {}
[Code] .....