I have encountered a problem with template class. I have made a template class that converts a value into a string, and then made another template class that converts string to T if its possible. Now I need to overload >> and << operators for type T.
template<typename T>
string toString (const T &value) // convert a value into a string {
ostringstream os;
//os << value;
return os.str();
[Code] ....
Code:
template<class T>
class Convert {
T data;
public:
Convert(const T& tData = T()) : data(tData)
[Code] ....
Why do we use operator? Is float and double function names below?
Code:
Convert<int>::operator<float> float();
Convert<int>::operator<double> double();
I have been trying to get this my class template to print out a string for me, however I am getting :
" error C679 ' No operator found which takes a right hand operand of type std:: string' "
I have tried various way to get this going however I cant get past this error. I understand that templates functions how ever i am not sure why i am not getting my string to be displayed.
#include <iostream>
#include <string.h>
using namespace std;
template<class T>
class BinaryTree {
struct Node {
[code].....
I'm trying to implement a simple template array class, but when i came into the operator< i actually have to use a template :
my code is something like :
template<typename _Type, std::size_t _Size>
class array {
public :
[Code] ......
but i am having an error of shadows template param 'class _Type' is it w/ the name conflict between the array template parameter and the function template parameter ?
Error1error C2955: 'DoubleLinkedListInterface' : use of class template requires template argument listdoublelinkedlist.h10
Error2error C2244: 'DoubleLinkedList<T>::DoubleLinkedList' : unable to match function definition to an existing declaration doublelinkedlist.cpp7
Error3 .cpperror C2244: 'DoubleLinkedList<T>::~DoubleLinkedList' : unable to match function definition to an existing declaration 12
.h
#pragma once
#include "DoubleLinkedListInterface.h"
#include "Node.h"
#include <iostream>
[Code]....
I have a generic template class with another template in one of its types. Now I want to specialize one of its methods for a particular (template) class, which leads to a compile error, however.
Here is the example:
#include <stdio.h>
template<typename Type>
class Obj1 {
public:
void ID() { printf("Object 1, size = %zu
[Code] .....
GCC ends with:
:35:27: error: type/value mismatch at argument 2 in template parameter list for ‘template<class Type, template<class> class O> class Foo’
:35:27: error: expected a class template, got ‘Obj2<Type>’
What is wrong with the specialization? Can it even be achieved and how (if so)?
how I want the code to look. Only problem is it doesn't work (Line 11). I have some experience with templates but I'm not a pro.
Basically I want the "Channels<3>" to be a type that I can use to specify a Cable with similar to vector<float/int> it would be Cable<Channels<2 or 3>>.
What have I messed up with the syntax?
#include <iostream>
#include <vector>
using namespace std;
[Code].....
I have a class like this
PHP Code:
template<class X>
class A {
X m_x;
public:
X* foo();
X* bar();
//others are not related to X
};
I would like to get rid of
PHP Code: template<class X>
For class level but still use it for members. Like this
PHP Code:
class A {
X m_x;
public:
template<class X>
X* foo();
template<class X>
X* bar();
//others are not related to X
};
However, I am still stuck at
PHP Code: X m_x;
Let me put it into the code snippet:
/**
This class build the singleton design pattern.
Here you have full control over construction and deconstruction of the object.
*/
template<class T>
class Singleton
[Code]....
I am getting error at the assertion points when i call to the class as follows:
osgOpenCL::Context *cxt = osgOpenCL::Singleton<osgOpenCL::Context>::getPtr();
I tried commenting assertion statements and then the debugger just exits at the point where getPtr() is called.
How to initialize a static member of a class with template, which type is related to a nested class?
This code works (without nested class):
#include<iostream>
using namespace std;
struct B{
B(){cout<<"here"<<endl;}
};
template<typename Z>
[Code] ,....
I'm making a minimal spanning tree class that inherits a graph class, both are templated. This is my mstree.h so far:
#ifndef _MSTREE_H_
#define _MSTREE_H_
#include "graph.h"
namespace MSTreeNameSpace
[Code]...
and I keep getting these errors:
mst.h:9:25: error: expected template-name before ‘<’ token
class MST : public Graph<T>
^
mst.h:9:25: error: expected ‘{’ before ‘<’ token
mst.h:9:25: error: expected unqualified-id before ‘<’ token
I am trying to pass a class as a type to a template class. This class's constructor needs an argument but I cannot find the correct syntax. Is it possible?
Here is an example of what I described above. I did not compiled it, it is for illustrative purpose only. And of course argument val of the myData constructor would be doing something more useful than simply initializing an int....
template <class T>
class templateClass {
templateClass() {};
[Code]....
My real code would only compile is I add the myData constructor:
myData () {};
and gdb confirmed that it is this constructor that get called, even with dummy(4).
Ok, so I'm writing this code and when I build it keeps saying cannot implicitely convert type int to string even though I declared my variables as string. Why is it giving me this error?
private static string Repair()
{
string result="";
string beep;
string spin;
Console.WriteLine("Does your computer beep on startup?:(y,n)");
[Code]...
heres the function:
string ToString ( const char * format, ... )
{
char buffer[256];
[Code]....
these function do the same of the sprintf() function. but instead we use a variable for add the result, i want to return the result. when i use it:
string f;
f=ToString("hello world");
gives me several errors:
"error: crosses initialization of 'std::string f'"
"error: jump to case label [-fpermissive]"
I am using Visual Studio 2008. I just wonder if there are any library function in Windows SDK or MFC, or from third-parties, that can convert a UTF-8 string into Windows Unicode string(used in CString object).
Can MultiByteToWideChar or ATL String conversion macro like A2W to the conversion?
std::cout << "Hello C++ programmers!" << std::endl;
I am trying to create a LinkedList (and then, an ADT stack; // yes, I cannot use the STL stack because the teacher won't let me), and I am getting some weird error when I create a ListNode and declare LinkedList (which has the ListNodes!) a friend of it.
Here is my header-file code for both classes:
ListNode.h
#ifndef LISTNODE_H
#define LISTNODE_H
#include "LinkedList.h"
[Code]...
The errors I am getting are:
error: 'LinkedList' is not a class template
I have tried forward-declaring LinkedList in the ListNode.h file, but I get this error:
error: 'ListNode' does not name a type
Are there any other possible solutions to this problem; // without having to resort to crazy stuff like having a .h file #include a .cpp file, or even declaring and defining ALL OF MY CODE in the .h files???
I have this class templates And This UML.I have to write this function +operator=(source: Array<ElemType, SIZE>): Array<ElemType, SIZE> but I do not know how to start the declaration / or start the function. I have to return a template but I do not know how to do it,
UML
Array<ElemType, SIZE>
-elements: ElemType[SIZE]
+Array()
+Array(source: Array<ElemType, SIZE>)
+operator=(source: Array<ElemType, SIZE>): Array<ElemType, SIZE>
+operator==(other: Array<ElemType, SIZE>): Boolean
+operator!=(other: Array<ElemType, SIZE>): Boolean
<<L-value>>+operator[](index: Integer): ElemType
<<R-value>>+operator[](index: Integer): ElemType
[code]....
I want to use a template function of a class.
This is my code:
#include "Comparison.h"
#include <iostream>
using namespace std;
int main(int argc, char** argv) {
Comparison c;
[Code] ....
But I get the error message:
main.cpp:10: undefined reference to `int Comparison::max<int>(int, int)'
refer to the code below, the attribute class is created with the value type and default value, but why it doesn't work for std::string?
#include <string>
#include <iostream>
using namespace std;
[Code].....
The code below references to a header file and implementation .cpp file, which are not important. My question is what is the proper way to use a constructor in a main file. I have been getting "invalid use of" errors when using letters.Pair(a,b), where Pair(T a, T b) is a constructor that accepts arbitrary type T of variables 'a' and 'b'. So I played around a bit and suddenly found a syntax that works. I need verification for the syntax below:
#include <iostream>
#include "pair.h"
#include "pair.cpp"
[Code].....
Are the comments with the asterisks correct? As in this is always the way you initialize and assign? So letters.Pair(a, b) is not the right way to use constructors?
I have the following class header in library, but when i initialize in main the class, i have an error unresolved external symbols. So the class is not exported as it should.
Code:
template <typename Key, typename Value>
class UTILITIES_EXPORT MyMap : public QMap<Key, Value>
{
public:
MyMap() : QMap<Key, Value>() { }
[Code]....
I've defined a class with a copy constructor. Some sample code:
Class* c = new Class(*this) // My copy constructor must take in a const Class&
And the compiler gives:
error: cannot convert 'Class' to 'Class*' in initialization
Why does this syntax work with other data types? For example, int* MyInt = new int; compiles fine. What about a copy constructor makes it fail?
The following program is designed to demonstrate class templates. The program will evaluate postfix expressions input to the console by pushing them in a stack, and then popping them and evaluating them as such, (ex. entering 3 4 + would equal 3+4 = 7).
The code is below. We are not to modify it, but to fill in the blanks, the places filled in indicated with two asterisks for a line, and one on each side for a part of a line. If I didn't know what to enter (if anything), I put three ?s. If you want to copy and compile for yourself, look for all the *s and ?s.
1) I'm turning up all sorts of errors in the main program file (prog5.cpp) having to do with stacktype.cpp. It has been removed from the program, as it is included at the end of stackType.h. Most of them are "cannot convert 'this' pointer from StackType to StackType<stack> &'. How do I fix that?
2) The program supposedly lacks a default constructor, and it keeps turning up that 's' is an array of unknown size (do I call StackType or stack or what?).
stackType.h Code: #pragma once// Catherine Stringfellow and Trey Brumley
// A Stack is a data type, which stores values in an order where values are added to the top of the stack when pushed,
// and when popped, remove and return the value from the top of the stack.
// Class specification for Stack ADT in file StackType.h
using namespace std;
static const int MAXITEMS = 50;
[code].....
I have a list of numbers in an array created by a class template
Code:
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
using namespace std;
const int CAPACITY = 20;
template <class T>
class A
[code].....
I want to have a template function that is a member of a class. Is this possible? This code snippet is how I would think the syntax would go, although it doesn't compile. How would I achieve the same effect?
Code:
class myclass {
public:
int member ;
} ;
template <typename T> void myclass::func( T& arg )
[Code] .....
The code below doesn't compile. Two things to clear up:
1) I know x is going to be garbage.
2) I used the same type name label ElementType.
#include <iostream>
#include <ostream>
template <typename ElementType>
class Example {
[Code] .....