Dereferencing a pointer by multiple threads - c++

Question

In the example below, suppose I have a multithreaded queue i.e. supports multiple writes and reads from different threads (e.g. using mutex). We can see that 1. the pointer this as well as 2. the shared pointer m_mulque are passed to the readers and writers and my question is: Dereferencing the pointers this and m_mulque is thread safe or not? In other words is my following code thread safe or not meaning should I worry about any undefined behaviour if I run this please?
#include <mutex>
#include <queue>
struct multithreaded_queue
{
void push(const std::size_t i)
{
std::lock_guard lock(m_mutex);
m_queue.push(i);
};
void try_pop()
{
std::lock_guard lock(m_mutex);
m_queue.pop();
};
private:
std::queue<std::size_t> m_queue;
mutable std::mutex m_mutex;
};
class example
{
public:
example()
{
m_mulque = std::make_shared<multithreaded_queue>();
};
void run()
{
auto writer = [this]()
{
for (std::size_t i = 0; i < 1000; i++)
{
m_mulque->push(i);
};
};
auto reader = [this]()
{
for (std::size_t i = 0; i < 1000; i++)
{
m_mulque->try_pop();
};
};
std::thread writer1(writer);
std::thread reader1(reader);
std::thread reader2(reader);
writer1.join();
reader1.join();
reader2.join();
};
private:
std::shared_ptr<multithreaded_queue> m_mulque;
};
int main(int argc, char* argv[])
{
example ex;
ex.run(); //Is this thread safe to call?
};