auto func = (PFN_vkCreateDebugUtilsMessengerEXT) vkGetInstanceProcAddr(instance, "vkCreateDebugUtilsMessengerEXT");

if (func != nullptr) {

return func(instance, pCreateInfo, pAllocator, pDebugMessenger);

} else {

return VK_ERROR_EXTENSION_NOT_PRESENT;

}

auto func = (PFN_vkDestroyDebugUtilsMessengerEXT) vkGetInstanceProcAddr(instance, "vkDestroyDebugUtilsMessengerEXT");

if (func != nullptr) {

func(instance, debugMessenger, pAllocator);

}

std::optional<uint32_t> graphicsFamily;

std::optional<uint32_t> presentFamily;

bool isComplete() {

return graphicsFamily.has_value() && presentFamily.has_value();

}

VkSurfaceCapabilitiesKHR capabilities;

std::vector<VkSurfaceFormatKHR> formats;

std::vector<VkPresentModeKHR> presentModes;

void run() {

initWindow();

initVulkan();

mainLoop();

cleanup();

}

GLFWwindow* window;

VkInstance instance;

VkDebugUtilsMessengerEXT debugMessenger;

VkSurfaceKHR surface;

VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;

VkDevice device;

VkQueue graphicsQueue;

VkQueue presentQueue;

VkSwapchainKHR swapChain;

std::vector<VkImage> swapChainImages;

VkFormat swapChainImageFormat;

VkExtent2D swapChainExtent;

std::vector<VkImageView> swapChainImageViews;

VkPipelineLayout pipelineLayout;

void initWindow() {

glfwInit();

glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);

glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);

window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan", nullptr, nullptr);

}

void initVulkan() {

createInstance();

setupDebugMessenger();

createSurface();

pickPhysicalDevice();

createLogicalDevice();

createSwapChain();

createImageViews();

createGraphicsPipeline();

}

void mainLoop() {

while (!glfwWindowShouldClose(window)) {

glfwPollEvents();

}

}

void cleanup() {

vkDestroyPipelineLayout(device, pipelineLayout, nullptr);

for (auto imageView : swapChainImageViews) {

vkDestroyImageView(device, imageView, nullptr);

}

vkDestroySwapchainKHR(device, swapChain, nullptr);

vkDestroyDevice(device, nullptr);

if (enableValidationLayers) {

DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);

}

vkDestroySurfaceKHR(instance, surface, nullptr);

vkDestroyInstance(instance, nullptr);

glfwDestroyWindow(window);

glfwTerminate();

}

void createInstance() {

if (enableValidationLayers && !checkValidationLayerSupport()) {

throw std::runtime_error("validation layers requested, but not available!");

}

VkApplicationInfo appInfo{};

appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;

appInfo.pApplicationName = "Hello Triangle";

appInfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);

appInfo.pEngineName = "No Engine";

appInfo.engineVersion = VK_MAKE_VERSION(1, 0, 0);

appInfo.apiVersion = VK_API_VERSION_1_0;

VkInstanceCreateInfo createInfo{};

createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;

createInfo.pApplicationInfo = &appInfo;

auto extensions = getRequiredExtensions();

createInfo.enabledExtensionCount = static_cast<uint32_t>(extensions.size());

createInfo.ppEnabledExtensionNames = extensions.data();

VkDebugUtilsMessengerCreateInfoEXT debugCreateInfo{};

if (enableValidationLayers) {

createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());

createInfo.ppEnabledLayerNames = validationLayers.data();

populateDebugMessengerCreateInfo(debugCreateInfo);

createInfo.pNext = (VkDebugUtilsMessengerCreateInfoEXT*) &debugCreateInfo;

} else {

createInfo.enabledLayerCount = 0;

createInfo.pNext = nullptr;

}

if (vkCreateInstance(&createInfo, nullptr, &instance) != VK_SUCCESS) {

throw std::runtime_error("failed to create instance!");

}

}

void populateDebugMessengerCreateInfo(VkDebugUtilsMessengerCreateInfoEXT& createInfo) {

createInfo = {};

createInfo.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;

createInfo.messageSeverity = VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT;

createInfo.messageType = VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT;

createInfo.pfnUserCallback = debugCallback;

}

void setupDebugMessenger() {

if (!enableValidationLayers) return;

VkDebugUtilsMessengerCreateInfoEXT createInfo;

populateDebugMessengerCreateInfo(createInfo);

if (CreateDebugUtilsMessengerEXT(instance, &createInfo, nullptr, &debugMessenger) != VK_SUCCESS) {

throw std::runtime_error("failed to set up debug messenger!");

}

}

void createSurface() {

if (glfwCreateWindowSurface(instance, window, nullptr, &surface) != VK_SUCCESS) {

throw std::runtime_error("failed to create window surface!");

}

}

void pickPhysicalDevice() {

uint32_t deviceCount = 0;

vkEnumeratePhysicalDevices(instance, &deviceCount, nullptr);

if (deviceCount == 0) {

throw std::runtime_error("failed to find GPUs with Vulkan support!");

}

std::vector<VkPhysicalDevice> devices(deviceCount);

vkEnumeratePhysicalDevices(instance, &deviceCount, devices.data());

for (const auto& device : devices) {

if (isDeviceSuitable(device)) {

physicalDevice = device;

break;

}

}

if (physicalDevice == VK_NULL_HANDLE) {

throw std::runtime_error("failed to find a suitable GPU!");

}

}

void createLogicalDevice() {

QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;

std::set<uint32_t> uniqueQueueFamilies = {indices.graphicsFamily.value(), indices.presentFamily.value()};

float queuePriority = 1.0f;

for (uint32_t queueFamily : uniqueQueueFamilies) {

VkDeviceQueueCreateInfo queueCreateInfo{};

queueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;

queueCreateInfo.queueFamilyIndex = queueFamily;

queueCreateInfo.queueCount = 1;

queueCreateInfo.pQueuePriorities = &queuePriority;

queueCreateInfos.push_back(queueCreateInfo);

}

VkPhysicalDeviceFeatures deviceFeatures{};

VkDeviceCreateInfo createInfo{};

createInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;

createInfo.queueCreateInfoCount = static_cast<uint32_t>(queueCreateInfos.size());

createInfo.pQueueCreateInfos = queueCreateInfos.data();

createInfo.pEnabledFeatures = &deviceFeatures;

createInfo.enabledExtensionCount = static_cast<uint32_t>(deviceExtensions.size());

createInfo.ppEnabledExtensionNames = deviceExtensions.data();

if (enableValidationLayers) {

createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());

createInfo.ppEnabledLayerNames = validationLayers.data();

} else {

createInfo.enabledLayerCount = 0;

}

if (vkCreateDevice(physicalDevice, &createInfo, nullptr, &device) != VK_SUCCESS) {

throw std::runtime_error("failed to create logical device!");

}

vkGetDeviceQueue(device, indices.graphicsFamily.value(), 0, &graphicsQueue);

vkGetDeviceQueue(device, indices.presentFamily.value(), 0, &presentQueue);

}

void createSwapChain() {

SwapChainSupportDetails swapChainSupport = querySwapChainSupport(physicalDevice);

VkSurfaceFormatKHR surfaceFormat = chooseSwapSurfaceFormat(swapChainSupport.formats);

VkPresentModeKHR presentMode = chooseSwapPresentMode(swapChainSupport.presentModes);

VkExtent2D extent = chooseSwapExtent(swapChainSupport.capabilities);

uint32_t imageCount = swapChainSupport.capabilities.minImageCount + 1;

if (swapChainSupport.capabilities.maxImageCount > 0 && imageCount > swapChainSupport.capabilities.maxImageCount) {

imageCount = swapChainSupport.capabilities.maxImageCount;

}

VkSwapchainCreateInfoKHR createInfo{};

createInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;

createInfo.surface = surface;

createInfo.minImageCount = imageCount;

createInfo.imageFormat = surfaceFormat.format;

createInfo.imageColorSpace = surfaceFormat.colorSpace;

createInfo.imageExtent = extent;

createInfo.imageArrayLayers = 1;

createInfo.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;

QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

uint32_t queueFamilyIndices[] = {indices.graphicsFamily.value(), indices.presentFamily.value()};

if (indices.graphicsFamily != indices.presentFamily) {

createInfo.imageSharingMode = VK_SHARING_MODE_CONCURRENT;

createInfo.queueFamilyIndexCount = 2;

createInfo.pQueueFamilyIndices = queueFamilyIndices;

} else {

createInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;

}

createInfo.preTransform = swapChainSupport.capabilities.currentTransform;

createInfo.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;

createInfo.presentMode = presentMode;

createInfo.clipped = VK_TRUE;

createInfo.oldSwapchain = VK_NULL_HANDLE;

if (vkCreateSwapchainKHR(device, &createInfo, nullptr, &swapChain) != VK_SUCCESS) {

throw std::runtime_error("failed to create swap chain!");

}

vkGetSwapchainImagesKHR(device, swapChain, &imageCount, nullptr);

swapChainImages.resize(imageCount);

vkGetSwapchainImagesKHR(device, swapChain, &imageCount, swapChainImages.data());

swapChainImageFormat = surfaceFormat.format;

swapChainExtent = extent;

}

void createImageViews() {

swapChainImageViews.resize(swapChainImages.size());

for (size_t i = 0; i < swapChainImages.size(); i++) {

VkImageViewCreateInfo createInfo{};

createInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;

createInfo.image = swapChainImages[i];

createInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;

createInfo.format = swapChainImageFormat;

createInfo.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;

createInfo.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;

createInfo.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;

createInfo.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;

createInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;

createInfo.subresourceRange.baseMipLevel = 0;

createInfo.subresourceRange.levelCount = 1;

createInfo.subresourceRange.baseArrayLayer = 0;

createInfo.subresourceRange.layerCount = 1;

if (vkCreateImageView(device, &createInfo, nullptr, &swapChainImageViews[i]) != VK_SUCCESS) {

throw std::runtime_error("failed to create image views!");

}

}

}

void createGraphicsPipeline() {

auto vertShaderCode = readFile("shaders/vert.spv");

auto fragShaderCode = readFile("shaders/frag.spv");

VkShaderModule vertShaderModule = createShaderModule(vertShaderCode);

VkShaderModule fragShaderModule = createShaderModule(fragShaderCode);

VkPipelineShaderStageCreateInfo vertShaderStageInfo{};

vertShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;

vertShaderStageInfo.stage = VK_SHADER_STAGE_VERTEX_BIT;

vertShaderStageInfo.module = vertShaderModule;

vertShaderStageInfo.pName = "main";

VkPipelineShaderStageCreateInfo fragShaderStageInfo{};

fragShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;

fragShaderStageInfo.stage = VK_SHADER_STAGE_FRAGMENT_BIT;

fragShaderStageInfo.module = fragShaderModule;

fragShaderStageInfo.pName = "main";

VkPipelineShaderStageCreateInfo shaderStages[] = {vertShaderStageInfo, fragShaderStageInfo};

VkPipelineVertexInputStateCreateInfo vertexInputInfo{};

vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;

vertexInputInfo.vertexBindingDescriptionCount = 0;

vertexInputInfo.vertexAttributeDescriptionCount = 0;

VkPipelineInputAssemblyStateCreateInfo inputAssembly{};

inputAssembly.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;

inputAssembly.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

inputAssembly.primitiveRestartEnable = VK_FALSE;

VkPipelineViewportStateCreateInfo viewportState{};

viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;

viewportState.viewportCount = 1;

viewportState.scissorCount = 1;

VkPipelineRasterizationStateCreateInfo rasterizer{};

rasterizer.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;

rasterizer.depthClampEnable = VK_FALSE;

rasterizer.rasterizerDiscardEnable = VK_FALSE;

rasterizer.polygonMode = VK_POLYGON_MODE_FILL;

rasterizer.lineWidth = 1.0f;

rasterizer.cullMode = VK_CULL_MODE_BACK_BIT;

rasterizer.frontFace = VK_FRONT_FACE_CLOCKWISE;

rasterizer.depthBiasEnable = VK_FALSE;

VkPipelineMultisampleStateCreateInfo multisampling{};

multisampling.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;

multisampling.sampleShadingEnable = VK_FALSE;

multisampling.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

VkPipelineColorBlendAttachmentState colorBlendAttachment{};

colorBlendAttachment.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;

colorBlendAttachment.blendEnable = VK_FALSE;

VkPipelineColorBlendStateCreateInfo colorBlending{};

colorBlending.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;

colorBlending.logicOpEnable = VK_FALSE;

colorBlending.logicOp = VK_LOGIC_OP_COPY;

colorBlending.attachmentCount = 1;

colorBlending.pAttachments = &colorBlendAttachment;

colorBlending.blendConstants[0] = 0.0f;

colorBlending.blendConstants[1] = 0.0f;

colorBlending.blendConstants[2] = 0.0f;

colorBlending.blendConstants[3] = 0.0f;

std::vector<VkDynamicState> dynamicStates = {

VK_DYNAMIC_STATE_VIEWPORT,

VK_DYNAMIC_STATE_SCISSOR

};

VkPipelineDynamicStateCreateInfo dynamicState{};

dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;

dynamicState.dynamicStateCount = static_cast<uint32_t>(dynamicStates.size());

dynamicState.pDynamicStates = dynamicStates.data();

VkPipelineLayoutCreateInfo pipelineLayoutInfo{};

pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;

pipelineLayoutInfo.setLayoutCount = 0;

pipelineLayoutInfo.pushConstantRangeCount = 0;

if (vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayout) != VK_SUCCESS) {

throw std::runtime_error("failed to create pipeline layout!");

}

vkDestroyShaderModule(device, fragShaderModule, nullptr);

vkDestroyShaderModule(device, vertShaderModule, nullptr);

}

VkShaderModule createShaderModule(const std::vector<char>& code) {

VkShaderModuleCreateInfo createInfo{};

createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;

createInfo.codeSize = code.size();

createInfo.pCode = reinterpret_cast<const uint32_t*>(code.data());

VkShaderModule shaderModule;

if (vkCreateShaderModule(device, &createInfo, nullptr, &shaderModule) != VK_SUCCESS) {

throw std::runtime_error("failed to create shader module!");

}

return shaderModule;

}

VkSurfaceFormatKHR chooseSwapSurfaceFormat(const std::vector<VkSurfaceFormatKHR>& availableFormats) {

for (const auto& availableFormat : availableFormats) {

if (availableFormat.format == VK_FORMAT_B8G8R8A8_SRGB && availableFormat.colorSpace == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {

return availableFormat;

}

}

return availableFormats[0];

}

VkPresentModeKHR chooseSwapPresentMode(const std::vector<VkPresentModeKHR>& availablePresentModes) {

for (const auto& availablePresentMode : availablePresentModes) {

if (availablePresentMode == VK_PRESENT_MODE_MAILBOX_KHR) {

return availablePresentMode;

}

}

return VK_PRESENT_MODE_FIFO_KHR;

}

VkExtent2D chooseSwapExtent(const VkSurfaceCapabilitiesKHR& capabilities) {

if (capabilities.currentExtent.width != std::numeric_limits<uint32_t>::max()) {

return capabilities.currentExtent;

} else {

int width, height;

glfwGetFramebufferSize(window, &width, &height);

VkExtent2D actualExtent = {

static_cast<uint32_t>(width),

static_cast<uint32_t>(height)

};

actualExtent.width = std::clamp(actualExtent.width, capabilities.minImageExtent.width, capabilities.maxImageExtent.width);

actualExtent.height = std::clamp(actualExtent.height, capabilities.minImageExtent.height, capabilities.maxImageExtent.height);

return actualExtent;

}

}

SwapChainSupportDetails querySwapChainSupport(VkPhysicalDevice device) {

SwapChainSupportDetails details;

vkGetPhysicalDeviceSurfaceCapabilitiesKHR(device, surface, &details.capabilities);

uint32_t formatCount;

vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, nullptr);

if (formatCount != 0) {

details.formats.resize(formatCount);

vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, details.formats.data());

}

uint32_t presentModeCount;

vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount, nullptr);

if (presentModeCount != 0) {

details.presentModes.resize(presentModeCount);

vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount, details.presentModes.data());

}

return details;

}

bool isDeviceSuitable(VkPhysicalDevice device) {

QueueFamilyIndices indices = findQueueFamilies(device);

bool extensionsSupported = checkDeviceExtensionSupport(device);

bool swapChainAdequate = false;

if (extensionsSupported) {

SwapChainSupportDetails swapChainSupport = querySwapChainSupport(device);

swapChainAdequate = !swapChainSupport.formats.empty() && !swapChainSupport.presentModes.empty();

}

return indices.isComplete() && extensionsSupported && swapChainAdequate;

}

bool checkDeviceExtensionSupport(VkPhysicalDevice device) {

uint32_t extensionCount;

vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionCount, nullptr);

std::vector<VkExtensionProperties> availableExtensions(extensionCount);

vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionCount, availableExtensions.data());

std::set<std::string> requiredExtensions(deviceExtensions.begin(), deviceExtensions.end());

for (const auto& extension : availableExtensions) {

requiredExtensions.erase(extension.extensionName);

}

return requiredExtensions.empty();

}

QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device) {

QueueFamilyIndices indices;

uint32_t queueFamilyCount = 0;

vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, nullptr);

std::vector<VkQueueFamilyProperties> queueFamilies(queueFamilyCount);

vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, queueFamilies.data());

int i = 0;

for (const auto& queueFamily : queueFamilies) {

if (queueFamily.queueFlags & VK_QUEUE_GRAPHICS_BIT) {

indices.graphicsFamily = i;

}

VkBool32 presentSupport = false;

vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);

if (presentSupport) {

indices.presentFamily = i;

}

if (indices.isComplete()) {

break;

}

i++;

}

return indices;

}

std::vector<const char*> getRequiredExtensions() {

uint32_t glfwExtensionCount = 0;

const char** glfwExtensions;

glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);

std::vector<const char*> extensions(glfwExtensions, glfwExtensions + glfwExtensionCount);

if (enableValidationLayers) {

extensions.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);

}

return extensions;

}

bool checkValidationLayerSupport() {

uint32_t layerCount;

vkEnumerateInstanceLayerProperties(&layerCount, nullptr);

std::vector<VkLayerProperties> availableLayers(layerCount);

vkEnumerateInstanceLayerProperties(&layerCount, availableLayers.data());

for (const char* layerName : validationLayers) {

bool layerFound = false;

for (const auto& layerProperties : availableLayers) {

if (strcmp(layerName, layerProperties.layerName) == 0) {

layerFound = true;

break;

}

}

if (!layerFound) {

return false;

}

}

return true;

}

static std::vector<char> readFile(const std::string& filename) {

std::ifstream file(filename, std::ios::ate | std::ios::binary);

if (!file.is_open()) {

throw std::runtime_error("failed to open file!");

}

size_t fileSize = (size_t) file.tellg();

std::vector<char> buffer(fileSize);

file.seekg(0);

file.read(buffer.data(), fileSize);

file.close();

return buffer;

}

static VKAPI_ATTR VkBool32 VKAPI_CALL debugCallback(VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity, VkDebugUtilsMessageTypeFlagsEXT messageType, const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData, void* pUserData) {

std::cerr << "validation layer: " << pCallbackData->pMessage << std::endl;

return VK_FALSE;

}

HelloTriangleApplication app;

try {

app.run();

} catch (const std::exception& e) {

std::cerr << e.what() << std::endl;

return EXIT_FAILURE;

}

return EXIT_SUCCESS;