Understood it fully today, after learning about static objects, everything is clear now.. :)

@MikeShah

Ай бұрын

Great!

Beautiful explanation mike! I had trouble on understanding why people would use Singletons and how static memory worked! Keep up the great work, you are INSANELY underrated! One of the best! :)

@MikeShah

3 ай бұрын

Cheers, thank you for the kind words!

Best explanation of Singleton ever! Thanks Mike!!

@MikeShah

Жыл бұрын

Thank you for the kind words!

Thanks!

@MikeShah

Жыл бұрын

Amazing, thank you for the wonderful and generous donation!

@robertstrickland9722

Жыл бұрын

@@MikeShah Generous donation for generous (and thorough) coursework!

@MikeShah

Жыл бұрын

@@robertstrickland9722 more to come!

Holy smokes, three weeks into learning C++ with only two semester of MATLAB behind me 10 years ago and I guess correctly on static, sort of as I though static_cast would be answer.

you are genius . 🙏

@MikeShah

3 ай бұрын

Thank you for the kind words!

Thank you so much for this. I experimented with "what if I wanted to replace the Logger* with std::unique_ptr". What was interesting is that I had to declare "std::unique_ptr Logger::s_instance;" outside the class and then "Logger::s_instance = std::make_unique();" inside GetInstance(), returning *s_instance. However, when I removed the declaration outside the class and had "std::unique_ptr s_instance = std::make_unique();" inside the GetInstance(), it instantiated new Logger instances. In your implementation, would you have had to delete the *s_instance somewhere or is this taken care of for us because it's static?

@MikeShah

Ай бұрын

Because it is static, it would be cleaned up on program termination :)

Just Loving it 🙏

@MikeShah

Жыл бұрын

Cheers!

Alternatively you can use "inline" to initialize static member objects inside a class, think this makes it more intuitive!

@MikeShah

3 ай бұрын

Yes! It actually makes things much more clean :)

great video, helps a lot !

@MikeShah

2 жыл бұрын

Thank you for the kind words!

Please do a video on proxy and skeleton design pattern

I'm having a bit of trouble trying to understand how you can initialize the s_instance on a global scale even though it's a private member of a class.

@MikeShah

Жыл бұрын

Couple of videos coming up on 'static' here: kzread.info/dash/bejne/mn2np5KBmbOXdZs.html and here kzread.info/dash/bejne/e4R3p6SBh8q4ops.html (to be released shortly) that I think will help clarify how 'static' variables in classes are shared amongst all instances of a class.

amazing!!!

@MikeShah

3 ай бұрын

Cheers!

Hello Mike, that is a very nice example of it! I have two questions, I understand we need to use mutex to be thread safe specially when we add new text to the log in this case, but why we should use mutex when GetInstance return the address of the object? since static will garantee we only have one copy of it. My second question is about the destructor, I notice it is never called, is this the standard behavior of singleton?, since the object needs to keep availble anytime if needed. Thanks Mike, awesome video!

@MikeShah

Жыл бұрын

Hi Carlos, Yes, correct on part one since we have static the variable will only be initialized once, and we'll only have one address returned so no need for a mutex. As for the destructor, static variables last the duration of the program, so the destruction is never called (it's kept available after the first allocation for the lifetime of the program). We could create a helper function to destroy any allocated memory if we truly wanted to, and sometimes folks will write a 'destroy' function, or a 'restart' type of function to reallocate.

@carlosrnardi

Жыл бұрын

Thanks@@MikeShah for the explanation, Your videos are awesome!!

@MikeShah

Жыл бұрын

@@carlosrnardi You are most welcome! Thank you for the kind words!

@_w62_

6 ай бұрын

@@MikeShah Would shared_ptr be the suitable choices for the 'restart' functions? If not, what would be the recommended patterns for resoure management in the singleton pattern? Thanks.

@MikeShah

6 ай бұрын

​@@_w62_Depends on what you are doing with the singleton -- in general we try to use unique_ptr, and in your restart() you could 'move' to a newly allocated pointer in 'restart'

Hi Mike I have a doubt , if we define a class member variable, then we need to allocate the memory by declaring the same variable outside class scope. But if we have a static variable in member function of a class we need not to declare the variable out side class for memory allocation. I could not understand how memory gets allocated for it, can you please explain. You have used static variable class function in singleton class design pattern video. Please explain this.

@MikeShah

7 ай бұрын

I believe the static variables inside of functions are allocated already -- the issue with the static class member variables is they need a concrete instantiation defined somewhere in a file (so the generated .object file knows where to store them).

@letslearn1703

7 ай бұрын

@@MikeShah Great video , thanks for your comments

@MikeShah

7 ай бұрын

@@letslearn1703 Cheers!

what if i like to use as below : #include #include #include using namespace std; class Singelton { private: vectormessage; Singelton(){ cout

@MikeShah

2 ай бұрын

That is also fine -- there's a variety of ways to setup singletons with some subtle trade-offs. If you use a pointer, then you only allocate if you use the Singleton for example. This may or may not matter depending on the size of the object.

Do you have courses on udemy?

@MikeShah

Жыл бұрын

My courses are all slowly migrating to courses.mshah.io

Hey! Great video, but I think this code might leak memory, because I didn't see the delete operator anywhere.

@pedrolobo9835

11 ай бұрын

How about? static Logger& GetInstance(){ static Logger sInstance; return sInstance; }

@MikeShah

11 ай бұрын

@@pedrolobo9835 I should probably delete the pointer, you're right. The trade-off is that. by using the pointer I don't have to allocate ever if I never use the class -- though of course I might cause a memory leak :)

@MikeShah

11 ай бұрын

Using std::unique_ptr would be the right thing to do in an even better implementation of singleton :)

Understood nothing... after 13:30

@MikeShah

Ай бұрын

This video on the 'static' keyword may be useful, as that is introduced at the 13:30 mark :) kzread.info/dash/bejne/mn2np5KBmbOXdZs.html

@user-ql7pw7ld1n

Ай бұрын

@@MikeShah Hi mike thanks for the video link.. I just saw full video. I am known to behavior of static , so only thing new is "static variables are stored in binary",...Now back to the main thing, in the singleton video, What I didnt understood is that --------> you are making a static instance of the class itself, that too inside the class.. This is really confusing..

@MikeShah

Ай бұрын

@@user-ql7pw7ld1n Constructor is private, so cannot be made. The way to get around that is to have a single 'static' (stored in the binary as you said) and you can instantiate that value at compile-time, or otherwise instantiate it in a public member function.

@user-ql7pw7ld1n

Ай бұрын

@@MikeShah ok...got an outline..im studying about "static instance" which is core concept of singleton ig...