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bind binded function as argument


bind binded function as argument

By : John Ades
Date : November 18 2020, 01:01 AM
it should still fix some issue The primary problem is that your bar_cb(T&&) doesn't deduce the template argument because the template argument is actually specified when using &foo::template bar_cb with some template argument X. The bind() expression will, however, copy the bound function, i.e., it may or may not have the type which would be deduced. Also, std::bind() will not pass bind()-expression through but will rather call them!
The easiest work around is to not use std::bind() to bind the function but rather to use a lambda function:
code :
template<typename T>
void bar(T&& t) {
    std::cout << "bar\n";
    doit([=](){ this->bar_cb(t); });
}
template <typename Fun>
class unbinder {
    Fun fun;
public:
    template <typename F>
    unbinder(F&& fun): fun(std::forward<F>(fun)) {}
    template <typename... Args>
    auto operator()(Args&&... args) const
        -> decltype(fun(std::forward<Args>(args)...)) {
        return fun(std::forward<Args>(args)...);
    }
};
template <typename Fun>
auto unbind(Fun&& fun)
    -> unbinder<Fun> {
    return unbinder<Fun>(std::forward<Fun>(fun));
}
template<typename T>
void bar_cb(T& t) {
    ...
}
f.bar(unbind(std::bind(lala)));
template<typename T>
typename std::enable_if<!std::is_bind_expression<typename std::decay<T>::type>::value>::type
bar(T&& t) {
    std::cout << "bar (non-bind)\n";
    doit(std::bind(&foo::template bar_cb<T>, this, std::forward<T>(t)));
}
template<typename T>
typename std::enable_if<std::is_bind_expression<typename std::decay<T>::type>::value>::type
bar(T&& t) {
    std::cout << "bar (bind)\n";
    doit(std::bind(&foo::template bar_cb<unbinder<T>>, this, unbind(std::forward<T>(t))));
}


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Using boost::bind with boost::function: retrieve binded variable type

Using boost::bind with boost::function: retrieve binded variable type


By : Abah
Date : March 29 2020, 07:55 AM
wish of those help As far as I know, you can't do what you want, as std::function throws away (nearly) all type information of the passed function pointer, function object or lambda. It employs a technique called type erasure and on the surface completely forgets what was passed into it, as long as it is callable with the provided arguments. So, after binding, you're out of luck it seems.
However, you can supply that information yourself:
code :
#include <functional>
#include <sstream>
#include <string>
#include <vector>

struct call_info{
  std::function<void(void)> func;
  std::string arg_type;
};

class MyClass{
  std::vector<call_info> _myVec;
  int _myInt;
  double _myDouble;

public:
  void foo1(int i);
  void foo2(double d);
  void bar();
  void execute(char* param);
};

void MyClass::bar(){
  call_info info;
  info.func = std::bind(&MyClass::foo1, this, &MyClass::_myInt);
  info.arg_type = "int";
  _myVector.push_back(info);
  info.func = std::bind(&MyClass::foo2, this, &MyClass::_myDouble);
  info.arg_type = "double";
  _myVector.push_back(info);
}

void MyClass::execute(char* param){
  call_info& info = _myVector[0];
  std::stringstream conv(param);

  if(info.arg_type == "int")
    conv >> _myInt;
  else if(info.arg_type == "double")
    conv >> _myDouble;
  info.func();
}
std::bind and different signature of calling binded function

std::bind and different signature of calling binded function


By : GFreeman
Date : March 29 2020, 07:55 AM
it should still fix some issue This code is conformant. The arguments that you pass to the result of bind are only used if needed.
code :
//N is the N from `std::bind(f, t1, ..., tN)`
For each i in 1 to N:
    if (ti is a reference wrapper) vi is the unwrapped version of t1
    if (ti is a bind_expression) vi is the result of calling ti with u1, ..., uM
    if (ti is a placeholder) vi is uj (where j is is_placeholder<decltype(ti)>::value)
    otherwise vi is ti
jQuery .bind binded function not firing

jQuery .bind binded function not firing


By : ebonysmm
Date : March 29 2020, 07:55 AM
it helps some times
don't use input event, it's not supported in many browsers, use keyup instead, it works on paste also
code :
$(document).ready(function() {
    $('#txtUserID').bind('keyup', function() {
        var inputValue = $(this).val();
        inputValue = inputValue.replace(/-/g, "");
        // and other replacements here, e.g.
        // inputValue = inputValue.replace(/(^.{7}|.{4})/g, "$1-");
        $(this).val(inputValue);
    });
});
Calling native bind function ( Function.prototype.bind ) without a context argument

Calling native bind function ( Function.prototype.bind ) without a context argument


By : Manpreet Kaur
Date : March 29 2020, 07:55 AM
around this issue You'll need to create your own binder function to do that. The main reason for having .bind() was to deal with the non-lexically defined this. As such, they didn't provide any way to use it without setting this.
Here's a simple example you could use:
In angular modal, the function bind to ng-click can't access new data binded from html input

In angular modal, the function bind to ng-click can't access new data binded from html input


By : vikram
Date : March 29 2020, 07:55 AM
it helps some times The following code snippet is a controller used for $modal.open(), I don't know why the ok function can't get latest data changed by data binding. , The problem is with scope. Change in view:
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