__VA_ARGS__ can be used multiple times, so you could write: #define PARSE_FUNCTION(functionName, …) \ std::function<int(__VA_ARGS__)> m_##functionName() { \ return std::function<int(__VA_ARGS__)>(functionName); \ } What is happening is just simple text substitution, whether the arguments is for a template or not won’t be checked by the preprocessor. Actually any function objects can be implicitly converted to a … Read more
It certainly depends on what the body of the loop does. With no body to the loop, both will just completely discard the entire loop. There’s nothing different about the code that can be generated in either case. The & case-A has the most likelihood of being able to discard needless operations (like copying values). … Read more
You included conio not conio.h you werent declaring std:: or using namespace std and one of your couts was just out. You may want to post the errors you get in the future and format your code. #include<iostream> #include<conio.h> long gcd(long,long); using namespace std; int main() { int m,n; cout<<“enter the 1st integer =”; cin>>m; … Read more
The idea is to calculate how the execution time for a piece of code – typically some algorithm, depends on the input. If a function takes N as input how long will it take to execute if N=5 or N=10. Will it take double as long? Will it take the same time? Or will it … Read more
You need to go from l to m when filling vector L: void merge(vector<int>& a, int l, int m, int r) { vector<int> L; vector<int> R; for (int i = l; i <= m; i++) L.push_back(a[i]); … } Otherwise L contains additional elements outside the range of interest. Then, index k steps off the end … Read more
If we need the second thread start to run after the first one is completed, is a thread really needed? For solution I think try to set a global flag, the set the value in the first thread, and when start the second thread, check the flag first should work. 2 solved How do I … Read more
static_assert works fine, is your code that never assert. The template struct X defines low and high as of type IntT. They are both the same type, whatever values they have. When you instantiate the struct (X<char,1,’a’> x) you are telling the compiler that the type of IntT is char and are giving to low … Read more
There are implicit and explicit conversions. A cast is always an explicit conversion and uses the (type) cast operator. C has quite decent type safety when it comes to pointers. Apart from the special case of null pointer conversions, the only implicit pointer conversion allowed is between an object pointer and a pointer to void. … Read more
Official build of MinGW (that compiler Dev-C++ uses) has no support for standard library threads now. You can use boost::thread as a drop in replacement (API is similiar enough) or use Microsoft Visual C++, or try programming with g++ on Linux (this is what I have done recently, using a virtual machine). 1 solved How … Read more
you are recreating the arr 11 time in your loop i think you meant to do this : //the error is generated because you are trying to access an element out of bounds because your declaration is wrong std::vector<MyClass> arr; for(unsigned long long i = 0 ; i<=10;i++){ arr.emplace_back( 10,20+i); std::cout << arr[i].ggg; } 0 … Read more
The return type of std::queue::pop() is void. Hence, you may not use: reverse.push(Q.pop()); You can use: reverse.push(Q.front()); Q.pop(); 0 solved Invalid use of void expression with a Queue and .pop()
Something like as follows. Hope that its understandable. Output:https://www.ideone.com/EnP40j #include <iostream> #include <iomanip> #include <cmath> int main() { float num1 = 95.345f; float num2 = 95.344f; num1 = roundf(num1 * 100) / 100; //rounding two decimals num2 = roundf(num2 * 100) / 100; //rounding two decimals std::cout << std::setprecision(2) << std::fixed << num1 << ” … Read more
In an unordered_set, the order of inserts does not necessarily correspond to the order that you will get when the set is iterated (hence the name “unordered”). Part of the reason why a bi-directional iterator is not supported(using a — operator) in this data structure is because being able to go backwards/forwards on an unordered_set … Read more
Can I make it work in my case somehow? Yes you can. You can either call it immediately after the definition: int median = [](std::vector<int> a) { std::sort(a.begin(), a.end()); return a[a.size() / 2]; }(v); //^^ –> invoke immediately with argument See for reference: How to immediately invoke a C++ lambda? or define the lambda and … Read more
You can avoid a circular include problem by using a forward declaration of a class instead of an #include: #ifndef ENTRANCE_H #define ENTRANCE_H #include <vector> #include “Diodio.h” class Segment; class Entrance { public: Entrance(); ~Entrance(); void operate(); protected: Segment *givesEntryTo; std::vector<Diodio> elBooths; std::vector<Diodio> manBooths; private: }; #endif // ENTRANCE_H (Entrance.cpp may or may not need … Read more