C++ :: Handling Static Cast Failures
Oct 10, 2014
Is it possible to handle situations where static cast fails. I have a sample code written belo:
typedef struct test {
int a;
int b;
} tester;
void setevent(void *in) {
tester *recv = static_cast<tester*>(in);
[Code] ....
In above code when setevent is called with the tester object, there is no issue, but if we pass random value it leads to seg fault. This is because static_cast is not type_safe, but can it be handled in any other way?
View 1 Replies
ADVERTISEMENT
Oct 10, 2013
Is there a difference between having static and dynamic cast in this scenario? The output is the same.
Code:
Base* pb = new Derived();
if(Derived* pd2 = static_cast<Derived*>(pb)) // true {
pd2->get_price(); // calls Base::get_price()
pd2->get_rate(); // calls Derived::get_rate()
[Code] ....
View 7 Replies
View Related
Feb 26, 2013
I have the next program: if I comment the assignation mNum=num; or mCh=ch the segmentation fault don't exist.
#include <vector>
class Base{
public:
[Code]....
View 2 Replies
View Related
Feb 9, 2015
I have an application that uses an array of threads to call a method along with thread.join(). I was just wondering what would be the best way to handle the thread in case if one of the thread fails? Should I put a try catch block on the method that is being called or should I put the try catch block on the array of threads, or is there any other proper way to handle failed threads?
View 3 Replies
View Related
Apr 17, 2013
From my book:
"A static function might have this prototype:
static void Afunction(int n);
A static function can be called in relation to a particular object by a statement such as the following:
aBox.Afunction(10);
The function has no access to the non-static members of aBox. The same function could also be called without reference to an object. In this case, the statement would be:
CBox::Afunction(10);
where CBox is the class name. Using the class name and the scope resolution operator tells the compiler to which class Afunction() belongs."
Why exactly cant Afunction access non-static members?
View 7 Replies
View Related
Sep 11, 2013
What are the workarounds for accessing the non-static member variables of some class(Say A) inside static member functions of another class(Say B)? I am coding in c++. Class A is derived with public properties of class B. Any pointers?
View 7 Replies
View Related
Aug 22, 2014
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?
View 2 Replies
View Related
Aug 5, 2013
Here is the code,
Code:
class A {
};
A& CreateObject() {
static A a;
return a;
} static A aa;
int main() {
return 0;
}
So is there any difference between a defined in CreateObject and aa?
View 6 Replies
View Related
Oct 2, 2014
Is it possible to get the string representation of an int. So I mean if i have: 5, I want to get '5'.
I was searching in the internet and I found this solution:
Code:
int number = 5;
char c = number + '0'; which works fine for small numbers, but if I do:
Code: int i;
char c;
for(i =0; i < 10000; i++) {
c = i + '0';
printf("%c
", c);
}
At some point some strange sings like %&/)/)$%&) are appearing, But i really need this huge numbers as well .. Is there any other way to do this??
View 8 Replies
View Related
Sep 29, 2013
How to cast an int to a string I came across this code:
#include <iostream>
#include <string>
int main(){
double f = 23.43;
std::string f_str = std::to_string(f);
std::cout << f_str << '
';
}
Unfortunately, using Dev C++ Version 5.4.2, I'm getting an error:
[Error] 'to_string is not a member of 'std'
View 2 Replies
View Related
Dec 7, 2013
In my refference book I have got a example with a part saying to access the a[4][0] element of the array (named a) with pointer this can be written:
*((int*)a+4)
I wonder if the cast is really required. The book says it is required so that the pointer arithmetic can be done properly. However I am not sure about it. When I work with pointers defined by myself I don't use casts similar to this one. Is there a difference between a self defined pointer and array name?
View 14 Replies
View Related
May 7, 2014
I have this program.
Code:
int test_variable;
int main() {
test_variable = (int)0x12;
}
Now my doubt is what is the advantage of type casting 0x12 to int. suppose if the test_variable data type is "char" then should i type cast to "char"?
View 6 Replies
View Related
Mar 14, 2012
Code:
namespace ConsoleApplication1 {
class ImplicitlyConvertibleFromFoo {
public ImplicitlyConvertibleFromFoo(Foo foo) {
this.foo = foo;
}
Foo foo;
[code]....
Any way to easily convert arrays of user-defined types?
View 7 Replies
View Related
Jun 20, 2013
Here is the code,
Code:
class B {
};
class D1:public B {
};
class D2:public D1 {
};
int main() {
B& b = dynamic_cast<B&>(*(new D2));
return 0;
}
D2 is actually grandchild of B, so D2 object reference can still be converted to B reference without any exception. Is it legal?
View 4 Replies
View Related
Mar 6, 2015
I am writing a program with FLTK and in event handling part wanted to send the address of the handler function to callback function. Type cast just does not work.
Code: btnOpenDB->callback(&FLUI::WndMain::DBOpenBtnClick_scb, reinterpret_cast<void*>(&WndMain::DBOpenBtnClick_cb));
I want to cast "a pointer to a class member function which accepts one argument" to a void pointer. After all it is just an address. So it is logically possible to cast it. Isn't it? Actually an static_cast should be enough!
View 9 Replies
View Related
Mar 18, 2013
The warning: :63:7: warning: passing argument 1 of fputc makes integer from pointer without a cast [enabled by default]
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
[Code]....
View 2 Replies
View Related
Dec 15, 2013
Code:
#include <stdio.h>
#include <stdlib.h>
#define CLASS 4
#define STUDENT 11
#define GRADE 5
[Code] ....
Giving me that error on 75:10
avesub+=grade[k];
and 90:17
donkeypunch+=grade[j][k];
not sure exactly why
View 8 Replies
View Related
Apr 18, 2014
I cannot get the following to compile. The problem is the printf on the last line. I understand that printf requires a char (or pointer to char). I understand that I can convert between datatypes by putting the target data type in parenthises in front of the variable. But how do I cast the integer into a character and then get it's pointer to pass into printf?
Following is my code. I compile with gcc temp.c -o temp.
Note that I have tried many attempts at that last line and this is just the one that I really, really think should work (or is at least the closest to the correct answer).
This code shown below, using printf("%s", &(char)nextChar); returns
temp.c:26: error: lvalue required as unary '&' operand
If I try to use printf("%s", *(char)nextChar); I get the error
temp.c:26: error: invalid type argument of 'unary *' (have 'int')
This line printf("%s", (char)nextChar); returns the obvious
format '%s' expects type 'char *', but argument 2 has type 'int'
Code:
#include <stdio.h>
int main() {
printf("hello, world
");
#if defined(SUNDIALS_EXTENDED_PRECISION)
[Code] ....
View 5 Replies
View Related
Apr 10, 2015
I have a library function with a prototype:
Code:
void func(unsigned char* in);
I would like to pass a std::string to it, so I tried:
Code:
std::string temp = "Hello!";
func((unsigned char*)temp.c_str());
This works, but I thought it was good practice for type safety to use C++ style casting, yet reinterpret_cast does not work in this instance as it fails:
ERROR: reinterpret_cast can not cast away const or other type qualifiers
and const_cast fails with:
ERROR: a const_cast can only adjust type qualifiers, it cannot change the underlying type
So what is the correct method of casting here assuming I can not change the library interface, and my data is kept in an std::string?
View 7 Replies
View Related
Jul 1, 2013
I've got two classes, which are both derived from the same two base classes. Here's a representation of the actual code:
Code: #include <vector>
class BaseClassA {
};
class BaseClassB {
};
class TestClassX
: public BaseClassA,
public BaseClassB
[code].....
Basically, I'd like to know if it is possible to cast directly from a BaseClassA pointer to a BaseClassB pointer, without casting to the child class first.
View 10 Replies
View Related
Jan 23, 2014
int hash = 0;
char *strings[100];
if((int)strings[i] != 0)
if((int) strings[hash] != 0)
while((int) strings[hash] != 0)
if((int)strings[hash] != 0)
if((int)strings[hash] != 0)
View 12 Replies
View Related
Oct 24, 2014
I programming currently something with OpenGL. Now I have written some wrapper classes, like Shader, Program .... All works fine, but I don't like to call Shader.GetHandle() every time I want to call a OpenGL function manually where I need the object handle/id. (GetHandle() returns the OpenGL ID of the object)
So now I wonder, is it possible to program it in C++ so, that I can put my objects to gl methods and c++ automatically pass the handle/id member to that function ? Is there maybe a operator that I can use for that?
For example:
The way I do it now:
Shader vertexShader();
glCompileShader(vertexShader.GetHandle());
The way I want to:
Shader vertexShader;
glCompileShader(vertexShader);
View 3 Replies
View Related
Aug 1, 2012
my array contains elements of integer type
how can i convert my array to long array
View 1 Replies
View Related
Mar 6, 2015
Code:
#include<stdio.h>
print_int_ptr(int *a){
printf(" a %i
" ,a);
printf(" &a %i
" ,&a);
[Code] .....
I get that warning : passing arg 1 of `print_int_ptr' makes pointer from integer without a cast|
View 3 Replies
View Related
Jan 18, 2015
Code:
#include <stdio.h>
int main(){
int a=15 ;
int b =20 ;
strcmp((a, "20") == 0) {
printf("Correct!");
[Code] .....
passing arg 1 of `strcmp' makes pointer from integer without a cast
View 11 Replies
View Related
Mar 26, 2014
I am having some errors with pointers and passing arguments.
Code:
#include <stdlib.h>
#include <stdio.h>
#define MAX_FILE_LENGTH 20
typedef struct node_{
int value;
struct node_* next;
[Code]....
View 3 Replies
View Related
