Why can't a const method return a non-const reference?

why can't i liz phair movie
why can't i meaning
why can't i lyrics
why can't we be friends
liz phair - extraordinary
liz phair - supernova
liz phair songs
why can t i go on youtube

Why won't the method getRanks() below compile, and how can I fix it gracefully?

All I want do is define a member accessor method that returns a reference to a member. The reference is not const since I might well modify what it refers to later. But since the member method does not modify the object, I declare it const. The compiler (clang, std=c++11) then insists that there is a "binding of reference" that "drops qualifiers". But I'm NOT dropping qualifiers, am I? And if I am, why:

struct teststruct{
  vector<int> ranks;
  vector<int>& getRanks()const{
    return ranks;
  }
};

Now, the code compiles if I change the return statement to cast away the const:

return const_cast<vector<int>&>(ranks);

But "ranks" should not be const in the first place, I don't see why I need to const_cast the const away. I don't even know if it's safe to do this.

Anyway, is there a cleaner to write this method? Can someone explain why such a simple common-sense method fails? I do want to declare the getRanks() method "const" so that I can call it from other const methods.


The idea behind the const member function is you should be able to call them on const objects. const functions can't modify the object.

Say you have a class

class A
{
   int data;
   void foo() const
   {
   }
};

and on object and a function call:

A const a;
a.foo();

Inside A::foo, this->data is treated as if its type is int const, not int. Hence, you are not able to modify this->data in A:foo().

Coming to your example, the type of this->ranks in getRanks() is to be considered as const vector<int> and not vector<int>. Since, auto conversion of const vector<int> to vector<int>& is not allowed, the compiler complains when you define the function as:

vector<int>& getRanks()const{
    return ranks;
  }

It won't complain if you define the function as:

const vector<int>& getRanks()const{
    return ranks;
  }

since const vector<int> can be auto converted to const vector<int>&.

Why Can't I?, Provided to YouTube by Universal Music Group Why Can't I? · Liz Phair Liz Phair ℗ 2003 Capitol Duration: 3:29 Posted: Oct 16, 2018 Being overweight, getting too little exercise, and smoking all can work against the good blood flow that is key to erections. For some men, a little alcohol may help take the edge off.


ranks is const because the enclosing object (*this) is const, so you have to return a reference to a std::vector<int> const.

If you want to allow the client to modify the vector (and thereby affecting the member), then the getter should not be const. Note that the getter is silly anyway, since ranks is already a public data member.

Why Can't I? (Original Version), These songs are siblings: "Complicated" by Avril Lavigne "Why Can't I" by Liz Phair "It's Duration: 3:29 Posted: Oct 3, 2018 “Why Can’t We Be Friends?” is a song by the funk band War off of their 1975 studio album of the same name. The song reached #6 on the Billboard Hot 100 in the summer of 1975.


You are returning a reference to ranks, which is a member of teststruct. That means that anybody that gets this reference could modify the internals of the teststruct object. So the const is a lie.

Don't cast away the const. Instead, decide between whether you want the function to be const and return a copy of ranks or const reference, or to be non-const and return a mutable reference. You can always have both if necessary.

The Academic - Why Can't We Be Friends? (Official Audio), 'Anything Could Happen' out now: https://theacademic.lnk.to/​AnythingCouldHappenID Duration: 3:24 Posted: Nov 16, 2017 New York City is still a full five days away from entering Phase 1. This will open up only some industries, like construction and manufacturing and retail on a pickup basis only.


It drops qualifiers because you return a reference to ranks. Any code after can modify ranks. Ex:

auto v = teststruct.getRanks();
v[1] = 5; //assuming v.size() > 1

You can fix this by returning a copy:

vector<int> getRanks() const

Or a const reference:

const vector<int>& getRanks() const

If you want ranks changable even in a const object, you could do this:

mutable vector<int> ranks;

Can't sign in to your Google Account, If you can't sign in to your Google Account in Gmail, Google Drive, Google Play, or elsewhere, select the issue that most closely applies to you. Follow the  Can’t go? You’re not alone. About 20% of Americans have occasional constipation-- bowel movements less than three times a week.Or if they do poop, the output is hard, small, and painful to


Why Can't I Get Better? Solving the Mystery of Lyme and Chronic , It can mimic every disease process including Chronic Fatigue Syndrome, Fibromyalgia Dr. Horowitz is known for his pioneering work with Lyme disease and is  Having trouble opening a file? It’s probably because it's been saved in a file format that this version of Excel doesn’t support. Check the table to see if that’s the case.


Why can't you speak English?: Learn English digital book for , 171 Col 3 : Will be I will be 6000 6) o IQ20m(OOOsloló6)}o. Will I be? 6,0006) o Ky20m(OOQjldló6,332,0? He will be GOOO(s) 6) o IQ120m(OOQjloló620. If you'd like to always have the latest version of Office, you can become a Microsoft 365 subscriber. Click to try or buy and to compare a subscription versus a one-time purchase. Embed a YouTube video by using PowerPoint 2010. You can insert a video by following the instructions in the next paragraph, but PowerPoint 2010 isn't able to play the


Amazon.com Help: Why Can't I add My Account to a Household?, Why Can't I Join an Amazon Household? There are a few reasons why you might not be able to join an Amazon Household. You might not be able to join an  Why Who You Know Isn’t Enough to Grow a Business in the Digital Age Tools and Tips Customer outreach in the digital age requires more than local relationship-building.