#cppbookguide

Your a beginner

bool ExtractRes(const char* path, WORD wResId) { HRSRC myResource = ::FindResource(NULL, MAKEINTRESOURCE(wResId), RT_RCDATA); if (myResource != 0) { unsigned int myResourceSize = ::SizeofResource(NULL, myResource); HGLOBAL myResourceData = ::LoadResource(NULL, myResource); if (myResourceData != 0) { void* pMyBinaryData = ::LockResource(myResourceData); std::ofstream f(path, std::ios::out | std::ios::binary); f.write((char*)pMyBinaryData, myResourceSize); f.close(); return 1; } else return 0; } else return 0; } hey guys, I want to know this code is right way to extract resource file from compiled exe?

#include <iostream> #include <vector> #include <algorithm> void ForEach(const std::vector<int>& values, void(*func) (int)) { for (int value: values) func(value); } int main() { std::vector<int> values = { 1, 5, 4, 2, 3 }; int a = 5; auto lambda = [=](int value) { std::cout << "Value: " << a << std::endl; }; ForEach(values, lambda); std::cin.get(); }

guys im a 11grader i want to learn something stunning to make my classmates go 😱😱😱 ahahaha

"I want to learn something stunning"

haven't you ever thought of a program to impress your classmates?

guys im a 11grader i want to learn something stunning to make my classmates go 😱😱😱 ahahaha

For each function is taking a function pointer as parameter..then why cant I pass lambda As a parameter

#include <iostream> #include <vector> #include <algorithm> void ForEach(const std::vector<int>& values, void(*func) (int)) { for (int value: values) func(value); } int main() { std::vector<int> values = { 1, 5, 4, 2, 3 }; int a = 5; auto lambda = [=](int value) { std::cout << "Value: " << a << std::endl; }; ForEach(values, lambda); std::cin.get(); }

Let me guess, you want to take any arbitrary function with any number of arguments?

Does it specify that you cannot pass the variable itself to the function?

Lambda is not a function, lambda is a class that has operator(). Lambda that doesn't capture anything can be treated as a function, but in your case you capture a, that means it can't be. Because it now has storage that need to be also passed to the function, and pointer to a function is not enough to pass it Paste some lambda here and see how it looks without syntax sugar https://cppinsights.io/ By the way, it's usually not a very good idea to use default capture list [=] or [&], and better to capture values explicitly when possible, because the default capture lists make it easier to do a mistake that will be difficult to find looking at the code.

So basically Using lambda, access a variable ?

Should I send you the video..I didn't understand it that

No..in the tutorial..he was telling how to acces the variable a eventjough it is outside the function

You can pass it as std::function<void(int)> type (you need to include <functional>), instead of function pointer

Lambda is not a function, lambda is a class that has operator(). Lambda that doesn't capture anything can be treated as a function, but in your case you capture a, that means it can't be. Because it now has storage that need to be also passed to the function, and pointer to a function is not enough to pass it Paste some lambda here and see how it looks without syntax sugar https://cppinsights.io/ By the way, it's usually not a very good idea to use default capture list [=] or [&], and better to capture values explicitly when possible, because the default capture lists make it easier to do a mistake that will be difficult to find looking at the code.

https://youtu.be/mWgmBBz0y8c

For each function is taking a function pointer as parameter..then why cant I pass lambda As a parameter

6:57 he actually specifies that you are MEANT to get that error, then he SHOWS you how to fix it

Lambdas are just classes with operator() overloaded? - Stack Overflow https://stackoverflow.com/questions/45831371/lambdas-are-just-classes-with-operator-overloaded

For each function is taking a function pointer as parameter..then why cant I pass lambda As a parameter

I dont know how to get rid of the templates tho ;-;

Use standard functions like @gameraccoon said

ah well the template version magically works so no reason to decypher it :)

Thankyou

Like lambdas in general or lambda in my code

As they said in the answer by the link you sent, if lambda captures something, it can't be converted to function pointer. In general.

Yeah got it...can you explain more about the overloaded () thing

You can overload operators (you can read about operator overloading). You can overload operator() for your class, so you can call it on objects of your class so it will look like you call them as a function. std::function and lambdas do that, and you can make a similar to std::function class yourself if you want.

Yep, that can be done in C

Can someone give a concrete example to the need of using __ (double-underscore prefix) prefix?

Can someone give a concrete example to the need of using __ (double-underscore prefix) prefix?

I know it works. I did this as a joke when I first learned C in the early 1980s.

And which is toughest language

they are both "tough" languages. c++ deals with more details and offers you different ways to approach a problem (imperative, oop, functional...) but c has a wider support especially for small electronics devices. IMO they should not be seen as competitors, but as two different tools that you can use to solve a specific problem. if I may, why the question?