Say I have overloaded functions with different arguments AND return types. Each set of argument has only one corresponding return type.
Code:
Vector grad(Scalar)
Tensor grad(Vector)
Later I have:
Code:
template <class T>
void test(T x) {
... Y = grad(x)
}
Then how do I automatically declare the type of Y. Do I need to make the grad function a template and specialize each of them ?
i heard that it was int but later it is deprecated , so at present what is the default return type of a function ?
View 4 Replies View RelatedI want my function to return the type mpz_t, but I'm not sure how?
I've tried: mpz_t MyFunction(mpz_t A, mpz_t B){}
But it didn't work, here is my code so far, I have bolded the parts of the code which are causing errors and added the errors in the comments:
Code:
#include <iostream>
#include <mpir.h>
using namespace std;
???? A(mpz_t m, mpz_t n){
mpz_t mmo; //used to store the value of m, minus one
[Code] .....
Is there a way around this?
I am having problems with my function definition of a function that should return a structure value.
This is the error I get compute.cpp(9): error C2146: syntax error : missing ';' before identifier 's_advertisebus'
The error is on the line where I start my function definition typing my function type as a structure. A long time ago in c the keyword struct is used with the structure type like struct s_advertisebus s_readadbus(). I tried it both ways but I got errors.
// struct.h
#ifndef STRUCT_H
#define STRUCT_H
struct s_advertisebus {
int nnumberofads;
float fpercentused;
[Code] ....
I always have confusions while using pointers with functions both as arguments and as return type.
View 1 Replies View RelatedIf we are using strcpy() for copying the string. As we are passing pointers to it It will copy the string & no need to return the string .This function will finely work with return type as void then why Ritchie has used it as char* strcpy()?
View 4 Replies View RelatedIs this really the preferred way to get the return type, for use in a derived class, of a function defined in the template parameter?
template<class PARAMETER> class C {
protected:
typedef typeof (reinterpret_cast<PARAMETER*>(0))->function() returntype;
};
This works just fine for me, but seems inelegant.
I have this code:
#include <iostream>
#include <vector>
#include <map>
#include <string>
using namespace std;
[Code]...
and it does not compile.
The error is:
test.cpp: In function ‘int main()’:
test.cpp:20:30: error: no matching function for call to ‘func1(std::vector<int>&)’
test.cpp:20:30: note: candidate is:
test.cpp:8:45: note: template<class T, class U> std::map<T, T> func1(U)
test.cpp:8:45: note: template argument deduction/substitution failed:
test.cpp:20:30: note: couldn't deduce template parameter ‘T’
I'm writing some functions pertaining to binary trees. I've used recursion once before while learning quicksort but am still quite new and unfamiliar with it. And this is my first time touching a binary tree. So my question: In my addnode function, will the return root statement at the end ever return a value other than the value passed to the function?
Code:
#include <stdlib.h>
struct tnode
{
int data;
struct tnode * left;
struct tnode * right;
}
[code]....
Code:
returnType operatorOperatorSymbol (parameterList); // syntax for operator overloading
Class Fraction
public:
Fraction operator-(const Fraction& f1){
Fraction r;
return r;
}
Is this even syntactically correct? It gives me errors. Im just trying to compile it without errors. I think the function makes sense since its returning a type Class
understand the below program.
Why I'm getting output y is 6.000000
Code:
#include <stdio.h>
int square(double a);
int main()
[Code].....
I am new to c++ and trying to learn. for instance. i have a struct and method.I am trying to learn what i can do with the method if i define the return type as struct type.
struct S {
int age;
string name;
};
S method() {
//what i can do in here. with the Struct. I mean can i reach members of the struct. etc
}
I am wondering why return type for an assignment operator cant be a void or int? Cant I write assignment operator for student class like this as we do nothing with returned value?
Student {
char name[20];
int marks;
public:
student(char*name,int marks)
[code].....
In my main I have a do/while loop, which is to iterate around the method calculateImportance while i is not equal to the numNodes.
do
{
int i;
int numNodes = Test.count();
for(i=0; i<=numNodes; i++)
[Code]....
I have been messing around with the data type node, hence why it is there are present, but, that doesn't seem to the answer
This is the function declaration in the header file.
node CalculateImportance();
i'm getting a new error is a wrong return type.
WebAPI.cs
namespace DarkAPP___WForm.Libs {
class WebAPI {
System.Net.WebClient wc = new System.Net.WebClient();
public WebAPI() {
[code].....
/*
* symboltable.c
*/
#include "symboltable.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "include/utlist.h"
[Code] ....
I am trying out a technique for a singleton class:
// access controlled singleton, accessed through function "instance()"
// singleton is constructed in this function
// so that constructor and destructor will be used
class single {
// private constructor/destructor
[Code] .....
Playing around with the code in main(), I am having trouble with auto:
single& s = single::instance(); // works fine
auto a = single::instance(); // error ~single() is private
When I make the destructor public, the output of the program is:
ctor
dtor
dtor
So I fixed this by typing auto&. I'm still confused though, why wouldn't auto know I am returning a reference?
I have a class where a method based on the type passed I should return a value.
prototype declared in the header file:
template <typename T>int getNum() const;
Code of the cpp file:
template <typename T> int class::getNum() const{
int c = 0;
for(int i=0;i<v.size();i++)
if(typeid(*(Pro*)v.at(i)) == typeid(T)) c++;
return c;
}
To invoke the method as I do:
ostream & operator << (ostream & os, Pro & obj) {
return os << obj.getNum();
}
I sew lot of sample for ASP WEB API. In althose link the post method is using
HttpResponseMessage as return tyope
Is it possible to use return type bool in WEB API post method?
I am writing a class Player which has several char arrays as private fields. I am trying to write a method which returns an array as a pointer, but doesn't alter the array in any way, thus the const.
Here is a snippet:
Code: class Player
{
private:
char state[MAX_STATE_CHAR + ONE_VALUE];
int rating;
char last[MAX_NAME_CHAR + ONE_VALUE];
char first[MAX_NAME_CHAR + ONE_VALUE];
int groupNumber = NEG_ONE;
public:
char * GetFirst() const
{
return first;
}
Visual studio is saying that the return type doesn't match.
I am trying to create a flexible interface for my CL application. And what i have is this :
Code:
using namespace std;
// iplcp -i queryFile -d databaseFile
template <typename INT, typename CHARA>
class API {
vector<string> files;
vector<INT> flags;
[Code] ....
and in main :
int main(int argc, char **argv){
//set variables
API<int, char**>args(argc,argv);
cout << "In file: "<< args.GetOpt("i") << " Db file: " << args.GetOpt("h") << endl;
}
// first thing to be printed should be string and the second int
I know this is not probably the best way to but i am laying around and was curious if something like this could work . Are there any good C++ templates for CLI applications from which i could learn?
I'm trying to pass 2 arrays into a void funtion, and return values to one function.
this is the the program I'm working with, after I'm done I have to split it into 3 files, a header, a main, and a separate cpp file for the functions to live in.
#include <iostream>
using namespace std;
void processArrary(int numberCount[], int Numbers[], int intnumberSize, int numberCountSize);
int main() {
int Scores[26] = {76, 89, 150, 135, 200, 76, 12, 100, 150, 28, 178, 189, 167, 200, 175, 150, 87, 99, 129, 149, 176, 200, 87, 35, 157, 189};
int numberCount[8] = { 0 };
[code]...
The goal of this program is to separate and count the groups of numbers then output the amount of numbers in each group. Near as I can tell, everthing should work, but I'm getting all zeros to be displayed in each group.
The function is supposed to return value from the file in my main, but I am getting empty value. I am trying to get better with pointer. Right now just teaching myself.
right now the only way for this code to show value is when in put the putchar(*ps) inside my readfile function. I would like to readfile to return value and print in the main function.
Code:
#include <stdio.h>
char *readfile(char filename[]);
int main(int argc, char *argv[] ) {
[Code].....
error says "cannot convert 'int*' to 'int' in function main()
and also
type mismatch in parameter in function sort(int,int)
Heres the code:
#include<iostream.h>
#include<conio.h>
void main() {
void sort(int,int);
clrscr();
[Code] .....
Why my function will not return this int. It does make it into the if(... prints "test 32" but will not return the given value(123456789).
#include <iostream>
using namespace std;
int lastZero(int x[]);
int main(){
int myArray[] = {1,1,1};
lastZero(myArray);
[Code] ...
I wanted to return a string I can do
Code:
string parseFilename(string fileName){
return fileName.subtr(/*blah*/);
}
Can I also use pointers/references here though? When would you use a pointer and when just a return statement?