I get linking errors when I use atomic functions in code. How could I solve it?

I don't use any special compiler or linker flags regarding the atomic library. I use it in code like this:

header file:

#include <atomic>

namespace some_namespace
{
class SomeClass
{
public:
    SomeClass(std::atomic_flag* ExclusiveOperation = nullptr)
    : exclusiveOperation(ExclusiveOperation)
    {}

    void someFunction(void);
private:
    void anotherFunction(void);
    std::atomic_flag* const exclusiveOperation{nullptr};
};
}

cpp file that implements class functions:

#include "header_file.hpp"

namespace some_namespace
{
void SomeClass::someFunction(void)
{
    if(exclusiveOperation != nullptr && exclusiveOperation->test_and_set())
    {}
}

void SomeClass::anotherFunction(void)
{
    if(exclusiveOperation != nullptr)

    {

        exclusiveOperation->clear();

    }

}

cpp file where class instance is created:

#include "header_file.hpp"

std::atomic_flag exclusiveOperation = ATOMIC_FLAG_INIT;
SomeClass someClassInstance(&exclusiveOperation);