i think it's safe, maybe this is why some symbols has the tag:

https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/_kernel/

The following kernel-mode libraries provide support for drivers: Core Kernel Library Support Routines Executive Library Support Routines Run-Time Library (RTL) Routines

#ifdef __cplusplus extern "C++" { template <typename _CountofType, size_t _SizeOfArray> char (*__countof_helper(_UNALIGNED _CountofType (&_Array)[_SizeOfArray]))[_SizeOfArray]; #define __crt_countof(_Array) (sizeof(*__countof_helper(_Array)) + 0) } #else #define __crt_countof(_Array) (sizeof(_Array) / sizeof(_Array[0])) #endif

This can be used only in those cases where the array is in scope. The original question how to get the size of an array when it is passed to a function. This method won't work there because the array would have decayed to a pointer by then. The only way around this is if the array is passed by reference (the msdn code you shared uses this concept) or if you pass a separate size argument to the function or if you use a sentinel value to mark the end of the array or if you pass iterators to the beginning and the end of the array

anyone has gate cse made easy course

anyone has gate cse made easy course

#meta

what

???

😂

😂

fine i will clarify my previous word. native api should not be used for general use except for specific case. Please correct me i'm wrong :"

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

int a = 1 *

Hi i am seeking help in webrtc. anyone knows?

Hi is there anyone who knows Vscode well?

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

Just test it

Can we initialise a char pointer like this: char* p = {'H','e','l','l','o','\0'};

Can we initialise a char pointer like this: char* p = {'H','e','l','l','o','\0'};

No

why?

No

I thought It's allowed

why?

Because it doesn't make any sense

but it compiles successfully in vs code by just giving warning

It cannot compile in VS Code, because VS Code is not a compiler

It cannot compile in VS Code, because VS Code is not a compiler

sorry i mean gcc compiler compiles it by just giving a warning

Please use pedantic with learning so you know what's allowed in standard and what is not.

sorry i mean gcc compiler compiles it by just giving a warning

It because the char treated as integer. You know ASCII value right

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

This is undefined in C, undefined in C++ versions lower than 17, and "1 1 3" for later versions (if you add the missing "a" to the int declaration)

This is undefined in C, undefined in C++ versions lower than 17, and "1 1 3" for later versions (if you add the missing "a" to the int declaration)

The standards didn't give specification for argument passing order ?

https://stackoverflow.com/questions/2934904/order-of-evaluation-in-c-function-parameters Found it

The suggestion is just dont use array they are boring prefer vectors

uhm vectors can be expensive

std::array is kinda better if you just need the size

std::array is kinda better if you just need the size

Vectors allocation are on heap while std::array is just wrapper to C array. https://devblogs.microsoft.com/oldnewthing/20230811-00/?p=108591

that's what im saying

std array is on the stack, no need for unnecessary heap allocation

How to find array size in a function in which array is passed as a parameter?

In C++, template <class T, std::size_t N> constexpr std::size_t size(const T (&array)[N]) noexcept { return N; } However, in production code, please visit this link and use the utility addressed, https://en.cppreference.com/w/cpp/iterator/size

Well I quite didn't get that but thanks all of you for answering my question yourself

Hi everyone, I'm a 17-year-old looking to start programming. I've heard that C++ is a good language to start with, but I'm wondering if it might be too challenging for a beginner. Can someone offer some advice?

Hi everyone, I'm a 17-year-old looking to start programming. I've heard that C++ is a good language to start with, but I'm wondering if it might be too challenging for a beginner. Can someone offer some advice?

I think that if you just want to learn language, c++ might be difficult; if you are just seeking to learn programming, c++ is okay choice to learn the basics (if you want to know some lower level stuff too).

Well I quite didn't get that but thanks all of you for answering my question yourself

well just use std::array instead of regular arrays, and use array.size() function. it's easy

Ok

I think that if you just want to learn language, c++ might be difficult; if you are just seeking to learn programming, c++ is okay choice to learn the basics (if you want to know some lower level stuff too).

To be honest, I am very interested in learning and using programming until I know how it works.

#include <array> int main() { std::array<int, 5> arr{1,23,3,5,2}; std::cout << arr.size() << std::endl; }

In C++, template <class T, std::size_t N> constexpr std::size_t size(const T (&array)[N]) noexcept { return N; } However, in production code, please visit this link and use the utility addressed, https://en.cppreference.com/w/cpp/iterator/size

This would work only if the array is in scope and since C++17 you can just use std::size(arr_name) to determine the array size as long as arr_name is actually an array and not a decayed pointer

Is it possible to create a content editor similar to what Corona Render has, using only Blueprint tools in Unreal Engine to ensure usability?

In C++, template <class T, std::size_t N> constexpr std::size_t size(const T (&array)[N]) noexcept { return N; } However, in production code, please visit this link and use the utility addressed, https://en.cppreference.com/w/cpp/iterator/size

The reason why I love and hate c++ at the same time

?

?

The above code block, I am not that good in modern c++. For me its like regex pattern code, understandable and make life easy (*love) but I am unable to make them work on my own, (*not hate) I just reuse them from google

In C++, template <class T, std::size_t N> constexpr std::size_t size(const T (&array)[N]) noexcept { return N; } However, in production code, please visit this link and use the utility addressed, https://en.cppreference.com/w/cpp/iterator/size

Correct me, That will not working on any raw array right ? int[], only std containers

The above code block, I am not that good in modern c++. For me its like regex pattern code, understandable and make life easy (*love) but I am unable to make them work on my own, (*not hate) I just reuse them from google

That is not Modern C++ code. That code would work even on a C++98 compiler.

That is not Modern C++ code. That code would work even on a C++98 compiler.

constexpr is from std 17?

constexpr is from std 17?

It is actually from C++11 but that function doesn't need constexpr or noexcept It would work even without that.

Correct me, That will not working on any raw array right ? int[], only std containers

It will work only on raw arrays that are in the scope in which the function is being called. It won't work on standard containers. You don't need such a function for standard containers. They all already provide a method called size

It is actually from C++11 but that function doesn't need constexpr or noexcept It would work even without that.

yes they are just some compiler optimizations

The standards didn't give specification for argument passing order ?

They don't specify argument evaluation order

It will work only on raw arrays that are in the scope in which the function is being called. It won't work on standard containers. You don't need such a function for standard containers. They all already provide a method called size

Uhh, ohk ye until compiler hold that info. I am just thinking it like some generic method to call size() like the top most example on the provided *Possible Implements*

Also I use sizeof(a.0)/sizeof a for raw array Any benefit like performance or something over it ?

Also I use sizeof(a.0)/sizeof a for raw array Any benefit like performance or something over it ?

You should just use std::size post C++17. No benefits between the choices as all of them are evaluated at compile time. The only problem with the function is that some inefficient compiler may cause template bloat where it creates versions of that function for each data type and data size. Most modern compilers won't.

You should just use std::size post C++17. No benefits between the choices as all of them are evaluated at compile time. The only problem with the function is that some inefficient compiler may cause template bloat where it creates versions of that function for each data type and data size. Most modern compilers won't.

Ye that's constexpr inline evaluation Won't be any problem with compiler, using clang as default

Hello everyone , so I declared a Struct with a member of type <vector>. For example: .... #include <vector> #define s 5 struct Student{ std::vector <int> v(s); }; This code is not running, when I created vector with a size, but if I make this: .... #include <vector> #define s 5 struct Student{ std::vector <int> v; }; The code execute. But when I created with the <array> it's running: .... #include <array> #define s 5 struct Student{ std::array <int,s> v; }; and also with std array or "int v[s];" this code is executing. Why that the class vector is not function when I create with a size?

Hello everyone , so I declared a Struct with a member of type <vector>. For example: .... #include <vector> #define s 5 struct Student{ std::vector <int> v(s); }; This code is not running, when I created vector with a size, but if I make this: .... #include <vector> #define s 5 struct Student{ std::vector <int> v; }; The code execute. But when I created with the <array> it's running: .... #include <array> #define s 5 struct Student{ std::array <int,s> v; }; and also with std array or "int v[s];" this code is executing. Why that the class vector is not function when I create with a size?

Hello everyone , so I declared a Struct with a member of type <vector>. For example: .... #include <vector> #define s 5 struct Student{ std::vector <int> v(s); }; This code is not running, when I created vector with a size, but if I make this: .... #include <vector> #define s 5 struct Student{ std::vector <int> v; }; The code execute. But when I created with the <array> it's running: .... #include <array> #define s 5 struct Student{ std::array <int,s> v; }; and also with std array or "int v[s];" this code is executing. Why that the class vector is not function when I create with a size?

You need to provide the size in struct constructor for vector

This would work only if the array is in scope and since C++17 you can just use std::size(arr_name) to determine the array size as long as arr_name is actually an array and not a decayed pointer

You have simply reiterated what I stated in my response. Revisit it and see that I ended by pointing to a link on cppreference.com; it is the page for std::size. Similar note, my implementation was picked straight out of the std::size example implementation, cause that is the overload of std::size that takes a built-in array.

Hello everyone , so I declared a Struct with a member of type <vector>. For example: .... #include <vector> #define s 5 struct Student{ std::vector <int> v(s); }; This code is not running, when I created vector with a size, but if I make this: .... #include <vector> #define s 5 struct Student{ std::vector <int> v; }; The code execute. But when I created with the <array> it's running: .... #include <array> #define s 5 struct Student{ std::array <int,s> v; }; and also with std array or "int v[s];" this code is executing. Why that the class vector is not function when I create with a size?

You are constructing a vector outside the constructor of Student.

Why?

offtopic, ad

By mistake

oh alr, i assumed you were a spambot anyway

No problem

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

1,2,2

Learning c++

1,2,2

or 3,3,1, or anything else

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

Isn’t it ub? I thought compilers can choose order of computing arguments

Isn’t it ub? I thought compilers can choose order of computing arguments

Yes, standards didn't say about evaluation order. https://t.me/programminginc/506760

This is undefined in C, undefined in C++ versions lower than 17, and "1 1 3" for later versions (if you add the missing "a" to the int declaration)

This is Unspecified Behavior in C++.

This is Unspecified Behavior in C++.

From C++17 onwards, it is specified as being left to right

From C++17 onwards, it is specified as being left to right

https://en.cppreference.com/w/cpp/language/eval_order This is the point that applies to this particular question. 15) In a function call, value computations and side effects of the initialization of every parameter are indeterminately sequenced with respect to value computations and side effects of any other parameter.

https://en.cppreference.com/w/cpp/language/eval_order This is the point that applies to this particular question. 15) In a function call, value computations and side effects of the initialization of every parameter are indeterminately sequenced with respect to value computations and side effects of any other parameter.

The fact that value computations and side effects of every parameter is indeterminably sequenced is what prevents Undefined Behavior. But this is still Unspecified Behavior as there is no specific order of evaluation of parameters

The fact that value computations and side effects of every parameter is indeterminably sequenced is what prevents Undefined Behavior. But this is still Unspecified Behavior as there is no specific order of evaluation of parameters

Oh, okay, my bad then

Uhh there's too much jargoan with explanations here and none touching the actual problem of interleaved instructions which are largely the root cause of the UB in this case.

Makes it very difficult for a beginner to follow tbh

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

The problem is the interleaving of instructions. Consider ++a as an expression, it is often broken up into two instructions temp = a + 1 // evaluate the expression a = temp // move the value to the variable Before C++11, for: fun(++a, ++a); You could have compiler interleave (reorder them) the instructions like this temp1 = a + 1 // value component temp2 = a + 1 // value component a = temp2 // side effect a = temp1 // side effect ... execution of fun(temp1, temp1) After C++11, more robust sequencing of operations for prefix and postfix operarions was introduced. In this case the value component would be sequenced before the side effect but that doesn't solvs the above interleaving problem as you can see for our particular case of what compiler can output After C++17 they are indeterminately sequenced, that is each ++a expression will finish first then the second so temp1 = a + 1 a = temp1 temp2 = a + 1 a = temp2 ... execution of fun(temp1, temp1+temp2) or temp2 = a + 1 a = temp2 temp1 = a + 1 a = temp1 ... execution of fun(temp2, temp1+temp2) can happen. Which makes it implementation defined unspecified behaviour.

what is the output of int = 1; printf("%d %d %d",a,++a,a++);

So in your case there's six possible outcomes depending on what gets executed first. 1 1 3 if a then a++ then ++a 1 2 2 if a then ++a then a++ 1 2 3 if a++ then a then ++a And so on