I am just learning using class template but I keep getting error unable to match function definition to an existing declaration
template <typename T>
class Homework {
private:
string name;
public:
template <typename T>
void SetName(T val);
[Code] ....
I've written the following code and keep getting the errors:
Error1error C2244: 'Supermarket<temp>::operator =' : unable to match function definition to an existing declaration
Error2error C2244: 'Supermarket<temp>::setName' : unable to match function definition to an existing declaration
Error3error C2244: 'Supermarket<temp>::setArea' : unable to match function definition to an existing declaration
#ifndef SUPERMARKET_H
#define SUPERMARKET_H
#include<string>
#include<iostream>
using namespace std;
[Code] .....
I moved the files to the .h file, and now I'm getting
Error2error LNK1120: 1 unresolved externals
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.
Basically I have a text file called words. I'm supposed to extract a word randomly from the file and have the user guess the word according to the definition.
I'm having trouble matching the definition to the word from the text file.
Here's my code:
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <ctime>
using namespace std;
int main(){
int number;
int count = 0;
string word;
[Code] ....
Here is my text file
apple#the usually round, red or yellow, edible fruit of a small tree
boat#a vessel for transport by water
horse#a solid-hoofed plant-eating domesticated mammal with a flowing mane and tail, used for riding
television#a system for transmitting visual images and sound that are reproduced on screens
soup#a liquid dish, typically made by boiling meat, fish, or vegetables, etc.
bottle#a container, typically made of glass or plastic and with a narrow neck
barber#a person who cuts hair
toast#sliced bread browned on both sides by exposure to radiant heat
radar#a system for detecting the presence, direction, distance, and speed of aircraft, ships, and other objects
red#of a color at the end of the spectrum next to orange and opposite violet
The compiler says my Rotor's cctor's definition doesn't match it's prototype.
Also, how can I convert my for loops into foreach loops?
Attached is the project.
I read that Memory is allocated during definition of a variable and not during declaration. Declaration is something like,
Code: int x;
And definition is assigning some value to it. This is what my professor taught. My doubt is if memory is not allocated during declaration, then how the compiler successfully compiles and runs the following, which i had already tried.
Code:
#include<stdio.h>
#include<conio.h>
int main() {
int c;
int *p=&c;
printf("%x",p);
getch();
return 0;
}
The variable c is only declared. But the program outputs a memory address. Shouldn't it show an error?
is possible to combine structures declaration and definition in programming language?
View 3 Replies View RelatedWhy I take warning on this code :
Code:
#include<stdio.h>
extern int v = 0; // Declaration and definition of an external
int main(void)
[code]...
Is there any error? Why I take a warning: 'v' initialized and declared 'extern'|||=== Build finished: 0 errors, 1 warnings ===| ???
and what is the meaning of :An extern declaration that initializes a variable serves as a definition of the variable. This rule prevents multiple extern declarations from initializing a variable in different ways.
i am using c language to program PIC micro controllers, i am making a multi compilation unit project in order to organize my code better.
I want to create an array of functions and be able to call it from anyplace in the code
what i have done so far gplib.c
Code:
typedef void (*out)(int8);
void OUT_A(int8 weight){output_A(weight);}
void OUT_B(int8 weight){output_B(weight);}
void OUT_C(int8 weight){output_C(weight);}
void OUT_D(int8 weight){output_D(weight);}
void OUT_E(int8 weight){output_E(weight);}
out output_port[5+1] = {OUT_A, OUT_B, OUT_C, OUT_D, OUT_E};
how to declare them in gplib.h and how to call them anywhere in the code.
Is this standard-compliant code?
int f() {
class C {
public:
int mf() const {return 1;}
};
C c;
return c.mf();
}
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 ?
In a .h file there is a function that takes in this parameter:
void (^callback)(float * arg)=NULL
as in a function definition:
void func(void (^callback)(float * arg)=NULL);
What I am able to read is that it takes a function pointer and if not defined it overrides with NULL. The part I do not get is the ^ in (^callback). I only know ^ as a bitwise XOR operator. It also generates issues in my VS2012 compiler (something with CLR). So I would really like to rewrite this part to something else, without the bitwise operator...
I have an issue converting VC++6 code to VC++ 2010. The following template function definition is not allowed by the new compiler:
template <> void AFXAPI DelElems <CBrush*> ( CPen** objects, int count ) {
for ( int i = 0; i < count; i++, objects++ )
if (*objects)
delete *objects;
}
All errors refer to the header of the template function:
- syntax error : '<'
- syntax error : missing ';' before '<'
- 'DelElems' : illegal use of type 'void'
- unrecognizable template declaration/definition
My question is while I'm reading this book step by step line by line, I reached this example. Building classes then derived classes. How can I add derived class from a class which is already existed. In other words, I have Person Class (which is my base class) and after implementing this class, I would like to create Student Class ( which is my derived class). How can I do that from using Solution Explorer window? I can add base class and derived class together by right click on my project and then add new item then adding class + base class I know that but what if my class in this case existed and I want only to add base class? I know how to add cpp. file and h. file but I want to take advantage of using the formal style if it exists in this case.
View 4 Replies View Relatedi want to use a class to print data stored as vector or array with different data types. i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns. so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class
i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata
{
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var)
{
[Code]....
then i want to call this template function in another ordinary function written in a seperate cpp file
these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions
i want to use a class to print data stored as vector or array with different data types.
i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns.so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class / i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata {
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var){
std::ofstream myfile;
std::string filename;
[code].....
then i want to call this template function in another ordinary function written in a seperate cpp file these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions.
class intClass{};
class stringClass{};
template <typename T>
class Mediator {
// bunch of code
};
I want Mediator<int> to declare intClass friend, Mediator<std::string> to declare stringClass friend etc..., without having to redefine the entire specialization
template<>
Mediator<int>::friend intClass;
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)'
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] .....
Firstly, is it legal to overload a template function in a class? This is what I did
class FILE_txt
{
public:
FILE_txt(const char* );
[Code]....
When we use a function template, we use a function template like a regular function, for example,
Code:
template<class T>
void foo(T t1, T t2)
{
}
foo(1,3);
Based on the arguments passed to foo, the compiler can deduct the type T. But on the other hand, when we use a class template, we always need to specify the type, for example,
Code:
template<class T>
struct sum {
static void foo(T t1, T t2)
{
}
};
sum<int>::foo(1,3);
Here we can't call sum::foo(1,3), otherwise we get compiler errors. My question is why the compiler can't deduct the type based on the arguments passed to foo? In addition, if we call function template foo like this,
Code:
foo(1, '3');
Then we get compiler errors. We need to specify the type like foo<int>(1.'3'). Since '3' can be always treated as integer, why we need to specify the type here?
I have in the past written code for templated functions where one function argument can be either a function pointer or a Functor. Works pretty straightforward.
Now I am in a situation where I am actually trying to pass a function pointer as template argument to a class. Unfortunately this does not work, I can pass the Functor class but not the function pointer. Below code illustrates the issue:
Code:
#include <string>
#include <iostream>
#include <sstream>
#include <cstdlib>
// For demonstration
const char * external_library_call() {
return "FFFF";
[Code] .....
The idea is to have the definition of the Record class simple and readable and have a maintainable way to add auto-conversion functions to the class. So the lines I commented out are the desirable way how I want my code to look. Unfortunately I could not come up with any way that was close to readable for solving this.
When I do this:
// header file:
#include <list>
using namespace std;
class myClass {
list<int> myMethod();
};
// cpp file:
list<int> myClass::myMethod() {
}
In the cpp file, 'myMethod' is underlined in red and when I hover over it, it says:
"std::list<int, std::allocator<int>> myClass::myMethod()
Error: declaration is incompatible with "<error-type> myClass::myMethod()""
But when I make it as a standalone function, outside a class, with no pre-declaration, there is no problem.
#include "IMyIntData.h"
class MyIntData : public CPMUnknown<IMyIntData>
{
I need to know what this syntax means (including MyIntData in angular brackets after parent class name) where IMyIntData is the Interface from where MyIntData is derived.
My program compiles fine and doesn't have any errors so I am confused as to what the issue might be.
I have a int, which is determined by the user via cin.
I have a char, which is a random word generated from an input file.
1. I want the program to display "The word you entered does match..." if the word entered by the user is the same as the random word.
2. I want the program to display "The word you entered does not match..." if the word entered by the user is not the same as the random word.
The code I'm using for number one is
if (char == "int") cout << "does match..."
The code I'm using for number two is
else if (char != "int") cout << "does not match..."
Basically the programs only outputs "does not match" whether or not it really matches. Even if it matches, it outputs does not match.
Is something wrong with my code?