How to initialize static std:array that uses static const variable as size? I tried searching for similar questions but std::array is relatively new so theres not much to be found.
// ExampleClass.h
class ExampleClass {
public:
static const size_t NUMBER_OF_INDEXES = 5;
private:
static std::array<int, NUMBER_OF_INDEXES> myArray;
};
Like any other static data member, ExampleClass::myArray should have an out-of-line definition in exactly one translation unit, where you write down its type and its qualified name as usual:
std::array<int, ExampleClass::NUMBER_OF_INDEXES> ExampleClass::myArray = {1, 2, 3, 4, 5};
Works fine with newer standards/compilers. I tried your code and it runs fine when using C++20 or C++23:
#include <array>
#include <stdint.h>
#include <iostream>
class ExampleClass {
public:
static const std::size_t NUMBER_OF_INDEXES = 5;
private:
static std::array<int, NUMBER_OF_INDEXES> myArray;
public:
void printSize(){
std::cout << myArray.size() << std::endl;
}
};
int main()
{
ExampleClass obj;
obj.printSize();
return 0;
}
https://onlinegdb.com/lVycEuQmE
P.S. For those who opened the question wondering if they can convert C-style array to std::array - yes, you can using C++20 std::to_array()
