logo
down
shadow

Variadic Variables by Reference


Variadic Variables by Reference

Content Index :

Variadic Variables by Reference
Tag : php , By : TheDave1022
Date : November 28 2020, 11:01 PM

I wish did fix the issue. I was hoping to create a method through which I could "bind" several variables by reference such that they can be reused to pass new data to an object, essentially doing the same thing that PHP's mysqli_stmt->bind_param() method does. , The syntax for variadic parameters by reference is:
public function bind(&...$vars) {
    ....
}

Comments
No Comments Right Now !

Boards Message :
You Must Login Or Sign Up to Add Your Comments .

Share : facebook icon twitter icon

How can arguments to variadic functions be passed by reference in PHP?


Tag : php , By : uxn
Date : March 29 2020, 07:55 AM
help you fix your problem There is no way of passing variable length argument lists by reference in PHP. It is a fundamental limitation of the language.
There is, however, a workaround with array(&$var1, &$var2...) syntax:
<?php

/** raise all our arguments to the power of 2 */
function pow2() {
        $args = &func_get_arg(0);

        for ($i = 0; $i< count($args); ++$i) {
            $args[$i] *= 2;
        }
}


$x = 1; $y = 2; $z = 3;
pow2(array(&$x, &$y, &$z)); // this is the important line

echo "$x, $y, $z"; // output "2, 4, 6"

?>

C++0x: how to get variadic template parameters without reference?


Tag : cpp , By : al.
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I don't understand your question. This code works fine with GCC and I see no reason why it shouldn't work.
#include <tuple>

template<typename... Args>
void something(Args... args)
{
  std::tuple<Args...> tuple{args...};
  std::get<0>(tuple) = 5;
}

int main() {
  int x = 10;
  something<int&>(x);
}

[js@HOST2 cpp]$ g++ -std=c++0x main1.cpp
[js@HOST2 cpp]$
template<typename... Args>
void something(Args... args)
{
  std::tuple<typename std::decay<Args>::type...> tuple;
  std::get<0>(tuple) = 5;
}

C++0x variadic template pass by reference


Tag : cpp , By : Will
Date : March 29 2020, 07:55 AM
wish of those help I want to use variadic template feature for my application but I don't want the objects to be passed by value (as objects are quite complex in my case). I want to pass them by reference (not as pointers). , Just say:
template <typename ...Args>
int myfunction(Args & ... args)
{
  /* ... */
}

c++ template variadic function undefined reference


Tag : cpp , By : SA.
Date : March 29 2020, 07:55 AM
help you fix your problem You CANNOT put template function into .cpp. you must put it into .h because compiler must know what the template is when specializing it.
your first main file
#include <iostream>
#include "TestTempB.h"
using namespace std;
using namespace ddl_lib;

int main() {
    string aa="15615";
    bool ccc=false;
    TestTempB b;
    b.callCommandA("name", &aa, &ccc);//undefined reference to `void ddl_lib::TestTempB::callCommandA<std::string*, bool*>(std::string const&, std::string*, bool*)'
}
#include <iostream>
#include <string>
using namespace std;

namespace ddl_lib {

class TestTempB {
public:
    TestTempB();
    virtual ~TestTempB();
    template<class ... Args>
    void callCommandB(const string&, const uint32_t*, Args ...);
    template<class ... Args>
    void callCommandA(const string&, Args ...);
};

} /* namespace ddl_lib */
using namespace ddl_lib;

int main() {
    string aa="15615";
    bool ccc=false;
    TestTempB b;
    b.callCommandA("name", &aa, &ccc);//undefined reference to `void ddl_lib::TestTempB::callCommandA<std::string*, bool*>(std::string const&, std::string*, bool*)'
}
#include <iostream>
#include <string>
using namespace std;

namespace ddl_lib {

class TestTempB {
public:
    TestTempB();
    virtual ~TestTempB();
    template<class ... Args>
    void callCommandB(const string&, const uint32_t*, Args ...);
    template<class ... Args>
    void callCommandA(const string&, Args ...);
};

template<class ... Args>
void TestTempB::callCommandB(const string& cmdName, const uint32_t* cmdSn, Args ... params) {
    cout << cmdName << endl;
}
template<class ... Args>
void TestTempB::callCommandA(const string& cmdName, Args ... params) {
    callCommandB(cmdName, NULL, params...);
}

} /* namespace ddl_lib */
using namespace ddl_lib;

int main() {
    string aa="15615";
    bool ccc=false;
    TestTempB b;
    b.callCommandA("name", &aa, &ccc);//undefined reference to `void ddl_lib::TestTempB::callCommandA<std::string*, bool*>(std::string const&, std::string*, bool*)'
}

Have rvalue reference instead of forwarding reference with variadic template


Tag : cpp , By : marocchino
Date : March 29 2020, 07:55 AM
Hope that helps I have a struct X and a function foo which must receive rvalue references of X. , The way to have a bunch of rvalue references is with SFINAE:
template <class... Args,
    std::enable_if_t<(!std::is_lvalue_reference<Args>::value && ...), int> = 0>
void foo(Args&&... args) { ... }
template <class... Args>
    requires (!std::is_lvalue_reference<Args>::value && ...)
void foo(Args&&... args) { ... }
template <class T>
concept NonReference = !std::is_lvalue_reference<T>::value;

template <NonReference... Args>
void foo(Args&&... ) { ... }
template <class... Args> auto foo(const Args&... args) = delete;
template <class... Args> auto foo(Args&... args) = delete;
Related Posts Related QUESTIONS :
  • Custom WordPress stylesheet not loading
  • Data attribute only returning first value
  • How to list all roles with Permissions,in spatie permission Package?
  • How to achieve this number pattern with n input
  • How to iterate array inside array data in laravel ,output are given below
  • To get output of movie with its genre
  • Extracting some data from a JS object literal string in PHP using Regex
  • axios and vuex are deleting wrong index in array
  • Setting empty CURLOPT_POSTFIELDS
  • Laravel 5.8 use subdomain as API endpoint beside domain.com/api
  • Error while add data in database SQL Server 2016
  • Does PhpStorm allow to skip PHPDoc tags when type hints is declared?
  • html classes are changed to Attributes
  • Using json to import multidimensional data
  • passing data from the view to the controller, where the data comes from another controller
  • How to extract integer and decimal numbers in PHP string correctly?
  • Parsing Sub-Object from an XML Feed with objects
  • Getting error "Unknown column 'text' in 'field list'"
  • How to properly get onedrive access token via php and curl
  • How to add spell check to a php function
  • Is it posible to create css rules with php?
  • Pretty URL with $_GET method
  • Wordpress always load same page - index.php
  • Find value in array and return with new from different array
  • PHP multiple file upload with different keys
  • Can't modify times one a time without weird errors
  • Get size of scraped image with domcrawler (Goutte)
  • Laravel - Ordering a collection of models
  • PHP Fatal error: Uncaught Error: Call to a member function setFetchMode() on boolean
  • Strict Standards: Only variables should be passed by reference in /main_dir/sub_dir/backup.php
  • Uncaught Google_Exception: (update) unknown parameter: 'copyRequiresWriterPermission'
  • Laravel 5 form does not redirect with old input
  • How to get values greater than or equal to in Mysql database sql when its a value like 1:00 PM?
  • PHP datediff overday issue
  • Masking an auto incrementing primary key
  • How to grab a String BEFORE a certain word
  • ZF2 Routing Multiple Controllers based on route constraints
  • How to deregister/dequeue jquery.sticky.js in Elementor (Pro)?
  • How to fix errors counting words in text plain with PHP?
  • How to get View data in Laravel in custom helper or directive
  • Creating a new data entry into a database with eloquent and trying to access the variable in the url
  • How to test authentication using Laravel Dusk?
  • PHP parse_str not getting all $_GET variables
  • Variable issues in php class
  • Get orders between dates in Codeigniter
  • Eloquent Special Chars Issue
  • Keeping leading zeros column Mysql
  • Current level navigation in Wordpress
  • Add a custom text to WooCommerce cart items if the product has a specific shipping class
  • Error connecting to CommissionJunction Token : [60] SSL certificate problem: unable to get local issuer certificate
  • How do I add a new key value pair to an object in PHP?
  • Http post request to php with dart
  • How to add a route in with blade into parameters of a component
  • How can i get the source of a 777 - CHMOD php file?
  • Convert 2010-04-16 16:30:00 to "Tomorrow Afternoon"
  • How can I hide a $_GET variable to be more secured in PHP?
  • Login to Gmail Inbox using Curl?
  • Upload Excel or CSV file to MySQL with PHP
  • Outlook Marking Email as Junk Email
  • Upload an image using class.upload.php via AJAX, display image in form using jQuery
  • shadow
    Privacy Policy - Terms - Contact Us © scrbit.com