diff --git a/src/vk/Buffer.cpp b/src/vk/Buffer.cpp
index 43bfba6..41231ba 100644
--- a/src/vk/Buffer.cpp
+++ b/src/vk/Buffer.cpp
@@ -61,7 +61,7 @@ Buffer::Buffer(Buffer&& other) noexcept
 }
 
 Buffer::~Buffer() noexcept {
-    if(is_valid()) {
+    if(!is_null()) {
         logger.warning() << "Buffer deleted before being destroyed";
         destroy();
     }
@@ -79,7 +79,7 @@ Buffer& Buffer::operator=(Buffer&& other) noexcept {
 
 
 VkMemoryRequirements Buffer::memory_requirements() const noexcept {
-    assert(is_valid());
+    assert(!is_null());
     assert(*m_context);
 
     VkMemoryRequirements memory_requirements;
@@ -94,7 +94,7 @@ VkMemoryRequirements Buffer::memory_requirements() const noexcept {
 
 
 void Buffer::bind_memory(const MemoryBlock& memory_block, VkDeviceSize offset) {
-    assert(is_valid());
+    assert(!is_null());
     assert(*m_context);
     assert(memory_block);
 
@@ -114,7 +114,7 @@ void Buffer::bind_memory(MemoryBlock&& memory_block) {
 }
 
 void Buffer::allocate_and_bind_memory(VkMemoryPropertyFlags memory_properties) {
-    assert(is_valid());
+    assert(!is_null());
     assert(*m_context);
 
     const auto memory_requirements = this->memory_requirements();
@@ -129,7 +129,7 @@ void Buffer::allocate_and_bind_memory(VkMemoryPropertyFlags memory_properties) {
 
 
 void Buffer::upload(size_t size, void* src_buffer, uint32_t dst_queue_family) {
-    assert(is_valid());
+    assert(!is_null());
     assert(*m_context);
 
     const bool use_staging_buffer =
@@ -166,7 +166,7 @@ void Buffer::upload(size_t size, void* src_buffer, uint32_t dst_queue_family) {
 
 
 void Buffer::destroy() noexcept {
-    assert(is_valid());
+    assert(!is_null());
     assert(*m_context);
 
     if(m_memory) {
diff --git a/src/vk/Buffer.h b/src/vk/Buffer.h
index 59e8859..a495d49 100644
--- a/src/vk/Buffer.h
+++ b/src/vk/Buffer.h
@@ -37,11 +37,11 @@ public:
     Buffer& operator=(Buffer&& other) noexcept;
 
     inline explicit operator bool() const {
-        return is_valid();
+        return !is_null();
     }
 
-    inline bool is_valid() const {
-        return m_buffer != VK_NULL_HANDLE;
+    inline bool is_null() const {
+        return m_buffer == VK_NULL_HANDLE;
     }
 
     inline Context* context() noexcept {
diff --git a/src/vk/Context.h b/src/vk/Context.h
index 6dd2822..82b7c7e 100644
--- a/src/vk/Context.h
+++ b/src/vk/Context.h
@@ -67,11 +67,11 @@ public:
     Context& operator=(const Context&) = delete;
 
     explicit inline operator bool() const {
-        return is_valid();
+        return !is_null();
     }
 
-    inline bool is_valid() const {
-        return m_instance != nullptr;
+    inline bool is_null() const {
+        return m_instance == nullptr;
     }
 
     VkInstance instance();
diff --git a/src/vk/Fence.cpp b/src/vk/Fence.cpp
index 03a81f1..2080292 100644
--- a/src/vk/Fence.cpp
+++ b/src/vk/Fence.cpp
@@ -36,7 +36,7 @@ Fence::Fence(Fence&& other) noexcept
 }
 
 Fence::~Fence() noexcept {
-    if(is_valid())
+    if(!is_null())
         destroy();
 }
 
@@ -51,7 +51,7 @@ Fence& Fence::operator=(Fence&& other) noexcept {
 
 VkResult Fence::get_status() const {
     assert(m_context);
-    assert(is_valid());
+    assert(!is_null());
 
     VkResult result = vkGetFenceStatus(
         m_context->device(),
@@ -66,7 +66,7 @@ VkResult Fence::get_status() const {
 
 void Fence::reset() {
     assert(m_context);
-    assert(is_valid());
+    assert(!is_null());
 
     if(vkResetFences(
         m_context->device(),
@@ -78,7 +78,7 @@ void Fence::reset() {
 
 void Fence::wait(uint64_t timeout) const {
     assert(m_context);
-    assert(is_valid());
+    assert(!is_null());
 
     wait_for_fences(
         m_context->device(),
@@ -90,7 +90,7 @@ void Fence::wait(uint64_t timeout) const {
 
 
 void Fence::destroy() noexcept {
-    assert(is_valid());
+    assert(!is_null());
     assert(m_context);
 
     vkDestroyFence(
diff --git a/src/vk/Fence.h b/src/vk/Fence.h
index dd80aaf..80f05d4 100644
--- a/src/vk/Fence.h
+++ b/src/vk/Fence.h
@@ -23,11 +23,11 @@ public:
     Fence& operator=(Fence&& other) noexcept;
 
     explicit inline operator bool() const noexcept {
-        return is_valid();
+        return !is_null();
     }
 
-    inline bool is_valid() const noexcept {
-        return m_fence != VK_NULL_HANDLE;
+    inline bool is_null() const noexcept {
+        return m_fence == VK_NULL_HANDLE;
     }
 
     inline const Context* context() const noexcept {
diff --git a/src/vk/Memory.cpp b/src/vk/Memory.cpp
index d8f5303..31b6304 100644
--- a/src/vk/Memory.cpp
+++ b/src/vk/Memory.cpp
@@ -42,7 +42,7 @@ MemoryBlock::MemoryBlock(MemoryBlock&& other) noexcept
 }
 
 MemoryBlock::~MemoryBlock() noexcept {
-    if(is_valid()) {
+    if(!is_null()) {
         logger.warning() << "MemoryBlock deleted before being freed";
         free();
     }
@@ -62,7 +62,7 @@ MemoryBlock& MemoryBlock::operator=(MemoryBlock&& other) noexcept {
 
 
 VkMemoryType MemoryBlock::memory_type_info(Context& context) const noexcept {
-    assert(is_valid());
+    assert(!is_null());
     assert(context);
 
     return context.memory_properties().memoryTypes[m_memory_type];
@@ -70,7 +70,7 @@ VkMemoryType MemoryBlock::memory_type_info(Context& context) const noexcept {
 
 
 void MemoryBlock::free() noexcept {
-    assert(is_valid());
+    assert(!is_null());
 
     m_memory_page->p_free(*this);
 
@@ -87,7 +87,7 @@ void* MemoryBlock::map(Context& context) {
 }
 
 void* MemoryBlock::map(Context& context, VkDeviceSize offset, VkDeviceSize size) {
-    assert(is_valid());
+    assert(!is_null());
     assert(context);
     assert(offset + size <= m_size);
 
@@ -106,7 +106,7 @@ void* MemoryBlock::map(Context& context, VkDeviceSize offset, VkDeviceSize size)
 }
 
 void MemoryBlock::unmap(Context& context) noexcept {
-    assert(is_valid());
+    assert(!is_null());
 
     vkUnmapMemory(
         context.device(),
@@ -116,7 +116,7 @@ void MemoryBlock::unmap(Context& context) noexcept {
 
 
 void MemoryBlock::flush(Context& context) {
-    assert(is_valid());
+    assert(!is_null());
 
     VkMappedMemoryRange range {
         .sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE,
@@ -133,7 +133,7 @@ void MemoryBlock::flush(Context& context) {
 }
 
 void MemoryBlock::invalidate(Context& context) {
-    assert(is_valid());
+    assert(!is_null());
 
     VkMappedMemoryRange range {
         .sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE,
diff --git a/src/vk/Memory.h b/src/vk/Memory.h
index e140c9c..e7f93d7 100644
--- a/src/vk/Memory.h
+++ b/src/vk/Memory.h
@@ -33,8 +33,8 @@ public:
         return m_size != 0;
     }
 
-    inline bool is_valid() const noexcept {
-        return m_size != 0;
+    inline bool is_null() const noexcept {
+        return m_size == 0;
     }
 
     inline VkDeviceSize size() const noexcept {
@@ -92,11 +92,11 @@ public:
     MemoryPage& operator=(MemoryPage&&);
 
     explicit inline operator bool() const noexcept {
-        return is_valid();
+        return !is_null();
     }
 
-    inline bool is_valid() const noexcept {
-        return m_size != 0;
+    inline bool is_null() const noexcept {
+        return m_size == 0;
     }
 
     inline VkDeviceSize size() const noexcept {
diff --git a/src/vk/RenderPass.cpp b/src/vk/RenderPass.cpp
index e1cbe99..8c4d3ff 100644
--- a/src/vk/RenderPass.cpp
+++ b/src/vk/RenderPass.cpp
@@ -32,7 +32,7 @@ RenderPass::RenderPass(RenderPass&& other) noexcept
 }
 
 RenderPass::~RenderPass() noexcept {
-    if(is_valid())
+    if(!is_null())
         destroy();
 }
 
@@ -46,7 +46,7 @@ RenderPass& RenderPass::operator=(RenderPass&& other) noexcept {
 
 
 void RenderPass::destroy() noexcept {
-    assert(is_valid());
+    assert(!is_null());
     assert(m_context);
 
     vkDestroyRenderPass(
diff --git a/src/vk/RenderPass.h b/src/vk/RenderPass.h
index db1b9e6..3814262 100644
--- a/src/vk/RenderPass.h
+++ b/src/vk/RenderPass.h
@@ -21,11 +21,11 @@ public:
     RenderPass& operator=(RenderPass&& other) noexcept;
 
     explicit inline operator bool() const noexcept {
-        return is_valid();
+        return !is_null();
     }
 
-    inline bool is_valid() const noexcept {
-        return m_render_pass != VK_NULL_HANDLE;
+    inline bool is_null() const noexcept {
+        return m_render_pass == VK_NULL_HANDLE;
     }
 
     inline operator VkRenderPass() noexcept {