C++11 compatible Linear Allocator

I have implemented a C++11 compatible linear or arena allocator. The code follows.

linear_allocator.hpp:

#pragma once

#include <cstddef>
#include <cassert>
#include <new>
#include "aligned_mallocations.hpp"

template <typename T>
class LinearAllocator
{
public:
    using value_type = T;
    using pointer = T*;
    using const_pointer = const T*;
    using reference = T&;
    using const_reference = const T&;
    //using propagate_on_container_copy_assignment = std::true_type;
    //using propagate_on_container_move_assignment = std::true_type;
    //using propagate_on_container_swap = std::true_type;

    LinearAllocator(std::size_t count = 64)
        : m_memUsed(0),
        m_memStartAddress(nullptr)
    {
        allocate(count);
    }
    ~LinearAllocator()
    {
        clear();
    }

    template <class U>
    LinearAllocator(const LinearAllocator<U>&) noexcept 
    {}

    /// \brief allocates memory equal to # count objects of type T
    pointer allocate(std::size_t count)
    {
        if (count > std::size_t(-1) / sizeof(T))
        {
            throw std::bad_alloc{};
        }
        if (m_memStartAddress != nullptr)
        {
            alignedFree(m_memStartAddress);
        }
        m_memUsed = count * sizeof(T);
        m_memStartAddress = static_cast<pointer>(alignedMalloc(m_memUsed, alignof(T)));
        return m_memStartAddress;
    }
    /// \brief deallocates previously allocated memory
    /// \brief Linear/arena allocators do not support free() operations. Use clear() instead.
    void deallocate([[maybe_unused]] pointer p, [[maybe_unused]] std::size_t count) noexcept
    {
        //assert(false);
        clear();
    }

    /// \brief simply resets memory
    void clear()
    {
        if (m_memStartAddress != nullptr)
        {
            alignedFree(m_memStartAddress);
            m_memStartAddress = nullptr;
        }
        this->m_memUsed = 0;
    }

    /// \brief GETTERS
    pointer getStartAddress() const
    {
        return this->m_memStartAddress;
    }
    std::size_t getUsedMemory() const
    {
        return this->m_memUsed;
    }
private:
    std::size_t m_memUsed;
    pointer m_memStartAddress;
};

template <class T, class U>
bool operator==(const LinearAllocator<T> &, const LinearAllocator<U> &)
{
    return true;
}

template <class T, class U>
bool operator!=(const LinearAllocator<T> &, const LinearAllocator<U> &)
{
    return false;
}

Don't worry about alignedMalloc and alignedFree. They are correct.

This is my test program (linear_allocator.cpp):

#include "linear_allocator.hpp"
#include <vector>
#include <deque>
#include <iostream>
#include <string>
#include <typeinfo>

int main()
{
    [[maybe_unused]]
    LinearAllocator<int> a{1024};
    std::cout << a.getStartAddress() << '\n';
    std::cout << a.getUsedMemory() << '\n';
    std::vector<std::string, LinearAllocator<std::string>> v;
    v.reserve(100);
    std::cout << "Vector capacity = " << v.capacity() << '\n';
    //std::cout << v.get_allocator().getStartAddress() << '\n';
    //std::cout << v.get_allocator().getUsedMemory() << '\n';
    v.push_back("Hello");
    v.push_back("w/e");
    v.push_back("whatever");
    v.push_back("there is ist sofi j");
    v.push_back("wisdom");
    v.push_back("fear");
    v.push_back("there's more than meets the eye");
    for (const auto &s : v)
    {
        std::cout << s << '\n';
    }
    std::cout << typeid(v.get_allocator()).name() << '\n';

    std::deque<int, LinearAllocator<int>> dq;
    dq.push_back(23);
    dq.push_back(90);
    dq.push_back(38794);
    dq.push_back(7);
    dq.push_back(0);
    dq.push_back(2);
    dq.push_back(13);
    dq.push_back(24323);
    dq.push_back(0);
    dq.push_back(1234);
    for (const auto &i : dq)
    {
        std::cout << i << '\n';
    }
    std::cout << typeid(dq.get_allocator()).name() << '\n';
}

Compiling with g++ -std=c++17 -O2 -march=native -Wall linear_allocator.cpp -o linear_allocator.gpp.exe and running linear_allocator.gpp.exe gives output:

0x4328b8
4096
Vector capacity = 100
Hello
w/e
whatever
there is ist sofi j
wisdom
fear
there's more than meets the eye
15LinearAllocatorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEE

As you can see deque's output isn't there at all. If I uncomment these 2 lines:

//std::cout << v.get_allocator().getStartAddress() << '\n';
//std::cout << v.get_allocator().getUsedMemory() << '\n';

will also not be displayed.

MSVS cl's output is the following:

000000B47A1CAF88
4096

which is even worse.

There must be something I am missing as there appears to be some UB, but I am unable to pinpoint where that is. My allocator design was based on C++11 + guidelines. I wonder what am I doing wrong.