C++ SFML Image loading fails on iter - c++

Question

I'm new to C++, in order to learn it better (I learn from doing) I have rewritten the code from an example C++ game I found over on GitHub, I intend to alter pieces of code to expand on it and change the graphics once I have it working in order to know exactly what does what. Rather than simply copying and pasting the existing code I made sure to write it all myself, I believe re-writing code gives a better understanding than simply copy&paste.
I'm trying to load images for a small game as a C++ test, when trying to execute the code from the IDE it keeps failing near if(iter == _images.end()) I have tried everything I myself can think of like changing the type of _images, changing how filename gets made, adding checks, removing checks, I have spent the last 3 days on Google and StackOverflow trying every fix I came accross that mentioned a similar problem. So far nothing has helped.
I will post the code sections I believe relevant to this here, please have a look and point me to where or how to fix this.
First things first, the error it shows me:
Exception thrown: read access violation.
std::_Tree<std::_Tmap_traits<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,sf::Texture,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::pair<std::basic_string<char,std::char_traits<char>,std::allocator<char> > const ,sf::Texture> >,0> >::_Root(...) returned 0x4.
If there is a handler for this exception, the program may be safely continued.
From what I have gathered this has to do with the memory it is trying to read/write to.
Call Stack
FileName.exe!std::_Tree<std::_Tmap_traits<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,sf::Texture,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::pair<std::basic_string<char,std::char_traits<char>,std::allocator<char> > const ,sf::Texture> >,0> >::_Lbound<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & _Keyval) Line 2060 C++
FileName.exe!std::_Tree<std::_Tmap_traits<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,sf::Texture,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::pair<std::basic_string<char,std::char_traits<char>,std::allocator<char> > const ,sf::Texture> >,0> >::lower_bound(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & _Keyval) Line 1538 C++
FileName.exe!std::_Tree<std::_Tmap_traits<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,sf::Texture,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::pair<std::basic_string<char,std::char_traits<char>,std::allocator<char> > const ,sf::Texture> >,0> >::find(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & _Keyval) Line 1481 C++
FileName.exe!VisibleGameObject::Load(std::basic_string<char,std::char_traits<char>,std::allocator<char> > filename) Line 17 C++
FileName.exe!Player::Player() Line 7 C++
FileName.exe!`dynamic initializer for 'speler''() Line 30 C++
[External Code]
VisibleGameObject.cpp
void VisibleGameObject::Load(std::string filename) {
filename = "textures/" + filename;
//Basic algorithm for images
auto iter = _images.find(filename);
if (iter == _images.end()) {
sf::Texture texture;
if (!texture.loadFromFile(filename)) {
std::cout << "[ERROR] Image failed to load!" << std::endl;
assert(false);
}
auto img = _images.insert(std::pair<std::string, sf::Texture>(filename, texture)).first;
std::cout << "[DEBUG] " + filename + ": Loaded and added to cache." << std::endl;
_sprite.setTexture(img->second);
_isLoaded = true;
}
else {
_sprite.setTexture(iter->second);
_isLoaded = true;
}
_imageKey = filename;
}
VisibleGameObject.h
#pragma once
#include "stdafx.h"
class VisibleGameObject {
public:
VisibleGameObject();
virtual ~VisibleGameObject();
virtual void Load(std::string filename);
virtual void Draw(sf::RenderWindow & window);
virtual void Update(float elapsedTime) = 0;
virtual void SetPosition(float x, float y);
virtual sf::Vector2f GetPosition() const;
virtual float GetWidth() const;
virtual float GetHeight() const;
virtual sf::Rect<float> GetBoundingRect() const;
virtual bool IsLoaded() const;
virtual bool ShouldPersist() const;
virtual void ToggleVisibility(bool isVisible);
virtual bool ShouldDraw() const;
protected:
sf::Sprite& GetSprite();
private:
sf::Sprite _sprite;
std::string _imageKey;
bool _isLoaded;
bool _shouldDraw;
static std::map<std::string, sf::Texture> _images;
};
stdafx.h
#pragma once
#include "targetver.h"
#include <stdio.h>
#include <tchar.h>
#include <SFML/System.hpp>
#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <SFML/Audio.hpp>
#include <map>
#include <iostream>
#include <cassert>
The call to VisibleGameObject.cpp happens from Game.cpp
void Game::Start() {
_mainWindow.create(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Window PlaceHolder Title");
Background *background1 = new Background(1);
background1->SetPosition(0.f, -768.f);
_gameObjectManager.Add("bg1", background1);
Background *background2 = new Background(2);
background2->SetPosition(0.f, -768.f);
_gameObjectManager.Add("bg2", background2);
Background *background4 = new Background(4);
background4->SetPosition(0.f, -768.f);
_gameObjectManager.Add("bg4", background4);
Player *player = new Player();
player->ResetStartingPosition();
_gameObjectManager.Add("player", player);
MainHUD *hud = new MainHUD();
_gameObjectManager.Add("hud", hud);
GameOverHUD *gameOver = new GameOverHUD();
_gameObjectManager.Add("gameover", gameOver);
while (!IsExiting()) {
GameLoop();
}
_mainWindow.close();
}
If anything is missing or I have added things that can be exluded, let me know and I will edit the question.