MInimal example of confiusion std::remove with remove from stdio.h

CMakeLists.txt

cmake_minimum_required(VERSION 3.7)
project(minimal_std)

set(CMAKE_CXX_STANDARD 11)

set(wxWidgets_ROOT_DIR /usr/include/wx-3.0)
find_package(wxWidgets COMPONENTS core base net REQUIRED)
include(${wxWidgets_USE_FILE})

add_definitions("-Werror=return-type -H")

set(SOURCE_FILES main.cpp main.h)
add_executable(minimal_std ${SOURCE_FILES})

target_link_libraries(minimal_std ${wxWidgets_LIBRARIES})

main.cpp

#include "main.h"
#include <wx/filename.h>
#include <vector>
#include <string>

wxIMPLEMENT_APP(MyApp);

MyFrame *mainFrame;

bool MyApp::OnInit() {
    MyFrame *frame = new MyFrame(NULL, wxID_ANY, "minimal_std", wxDefaultPosition, wxSize(800,600), wxDEFAULT_FRAME_STYLE);;
    frame->Show(true);
    mainFrame = frame;
    return true;
}

MyFrame::MyFrame(wxWindow *parent, wxWindowID id, const wxString &title, const wxPoint &pos, const wxSize &size, long style)
        : wxFrame(parent, id, title, pos, size, style) {
    std::vector<std::string> m_connections;
    //line below is problem, comment it to build
    m_connections.erase(std::remove(m_connections.begin(), m_connections.end(), nullptr), m_connections.end());
}

main.h

#ifndef MINIMAL_STD_MAIN_H
#define MINIMAL_STD_MAIN_H

#include <wx/wxprec.h>
#ifndef WX_PRECOMP
#include <wx/wx.h>
#endif

class MyApp : public wxApp
{
public:
    virtual bool OnInit();
};

class MyFrame : public wxFrame
{
public:
    MyFrame(wxWindow *parent, wxWindowID id, const wxString &title,
            const wxPoint &pos, const wxSize &size, long style);
};


#endif //MINIMAL_STD_MAIN_H