diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..922a91a
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,6 @@
+BasedOnStyle: LLVM
+IndentWidth: 4
+
+Language: Cpp
+DerivePointerAlignment: false
+PointerAlignment: Left
diff --git a/include/sirit/sirit.h b/include/sirit/sirit.h
index 728a4b7..5aee8b8 100644
--- a/include/sirit/sirit.h
+++ b/include/sirit/sirit.h
@@ -7,16 +7,15 @@
 #pragma once
 
 #include <cstdint>
-#include <set>
-#include <vector>
 #include <memory>
+#include <optional>
+#include <set>
 #include <spirv/unified1/spirv.hpp11>
+#include <vector>
 
 namespace Sirit {
 
-static const std::uint32_t GeneratorMagicNumber = 0;
-
-static const std::uint32_t Undefined = UINT32_MAX;
+constexpr std::uint32_t GENERATOR_MAGIC_NUMBER = 0;
 
 class Op;
 class Operand;
@@ -24,13 +23,14 @@ class Operand;
 typedef const Op* Ref;
 
 class Module {
-public:
+  public:
     explicit Module();
     ~Module();
 
     /**
      * Assembles current module into a SPIR-V stream.
-     * It can be called multiple times but it's recommended to copy code externally.
+     * It can be called multiple times but it's recommended to copy code
+     * externally.
      * @return A stream of bytes representing a SPIR-V module.
      */
     std::vector<std::uint8_t> Assemble() const;
@@ -46,19 +46,22 @@ public:
     void AddCapability(spv::Capability capability);
 
     /// Sets module memory model.
-    void SetMemoryModel(spv::AddressingModel addressing_model, spv::MemoryModel memory_model);
+    void SetMemoryModel(spv::AddressingModel addressing_model,
+                        spv::MemoryModel memory_model);
 
     /// Adds an entry point.
     void AddEntryPoint(spv::ExecutionModel execution_model, Ref entry_point,
-                       const std::string& name, const std::vector<Ref>& interfaces = {});
+                       const std::string& name,
+                       const std::vector<Ref>& interfaces = {});
 
     /**
      * Adds an instruction to module's code
-     * @param op Instruction to insert into code. Types and constants must not be emitted.
+     * @param op Instruction to insert into code. Types and constants must not
+     * be emitted.
      * @return Returns op.
      */
     Ref Emit(Ref op);
- 
+
     // Types
 
     /// Returns type void.
@@ -80,9 +83,9 @@ public:
     Ref TypeMatrix(Ref column_type, int column_count);
 
     /// Returns type image.
-    Ref TypeImage(Ref sampled_type, spv::Dim dim, int depth, bool arrayed, bool ms,
-                        int sampled, spv::ImageFormat image_format,
-                        spv::AccessQualifier access_qualifier = static_cast<spv::AccessQualifier>(Undefined));
+    Ref TypeImage(Ref sampled_type, spv::Dim dim, int depth, bool arrayed,
+                  bool ms, int sampled, spv::ImageFormat image_format,
+                  std::optional<spv::AccessQualifier> access_qualifier = {});
 
     /// Returns type sampler.
     Ref TypeSampler();
@@ -124,7 +127,7 @@ public:
     Ref TypePipe(spv::AccessQualifier access_qualifier);
 
     // Constant
-    
+
     /// Returns a true scalar constant.
     Ref ConstantTrue(Ref result_type);
 
@@ -135,10 +138,12 @@ public:
     Ref Constant(Ref result_type, Operand* literal);
 
     /// Returns a numeric scalar constant.
-    Ref ConstantComposite(Ref result_type, const std::vector<Ref>& constituents);
+    Ref ConstantComposite(Ref result_type,
+                          const std::vector<Ref>& constituents);
 
     /// Returns a sampler constant.
-    Ref ConstantSampler(Ref result_type, spv::SamplerAddressingMode addressing_mode,
+    Ref ConstantSampler(Ref result_type,
+                        spv::SamplerAddressingMode addressing_mode,
                         bool normalized, spv::SamplerFilterMode filter_mode);
 
     /// Returns a null constant value.
@@ -147,7 +152,8 @@ public:
     // Function
 
     /// Declares a function.
-    Ref Function(Ref result_type, spv::FunctionControlMask function_control, Ref function_type);
+    Ref Function(Ref result_type, spv::FunctionControlMask function_control,
+                 Ref function_type);
 
     /// Ends a function.
     Ref FunctionEnd();
@@ -155,21 +161,26 @@ public:
     // Flow
 
     /// Declare a structured loop.
-    Ref LoopMerge(Ref merge_block, Ref continue_target, spv::LoopControlMask loop_control,
+    Ref LoopMerge(Ref merge_block, Ref continue_target,
+                  spv::LoopControlMask loop_control,
                   const std::vector<Ref>& literals = {});
 
     /// Declare a structured selection.
-    Ref SelectionMerge(Ref merge_block, spv::SelectionControlMask selection_control);
+    Ref SelectionMerge(Ref merge_block,
+                       spv::SelectionControlMask selection_control);
 
-    /// The block label instruction: Any reference to a block is through this ref.
+    /// The block label instruction: Any reference to a block is through this
+    /// ref.
     Ref Label();
 
     /// Unconditional jump to label.
     Ref Branch(Ref target_label);
 
-    /// If condition is true branch to true_label, otherwise branch to false_label.
+    /// If condition is true branch to true_label, otherwise branch to
+    /// false_label.
     Ref BranchConditional(Ref condition, Ref true_label, Ref false_label,
-                          std::uint32_t true_weight = 0, std::uint32_t false_weight = 0);
+                          std::uint32_t true_weight = 0,
+                          std::uint32_t false_weight = 0);
 
     /// Returns with no value from a function with void return type.
     Ref Return();
@@ -188,10 +199,10 @@ public:
     static Operand* Literal(float value);
     static Operand* Literal(double value);
 
-private:
+  private:
     Ref AddCode(Op* op);
 
-    Ref AddCode(spv::Op opcode, std::uint32_t id = UINT32_MAX);
+    Ref AddCode(spv::Op opcode, std::optional<std::uint32_t> id = {});
 
     Ref AddDeclaration(Op* op);
 
diff --git a/src/insts.h b/src/insts.h
index 68f3998..b08b58a 100644
--- a/src/insts.h
+++ b/src/insts.h
@@ -6,13 +6,12 @@
 
 #pragma once
 
-#include "stream.h"
 #include "op.h"
+#include "stream.h"
 
 namespace Sirit {
 
-template<typename T>
-inline void AddEnum(Op* op, T value) {
+template <typename T> inline void AddEnum(Op* op, T value) {
     op->Add(static_cast<u32>(value));
 }
 
diff --git a/src/insts/constant.cpp b/src/insts/constant.cpp
index cf3b405..5bae45e 100644
--- a/src/insts/constant.cpp
+++ b/src/insts/constant.cpp
@@ -19,13 +19,13 @@ Ref Module::ConstantFalse(Ref result_type) {
 }
 
 Ref Module::Constant(Ref result_type, Operand* literal) {
-    Op* op{new Op(spv::Op::OpConstant, bound, result_type)};
+    auto const op{new Op(spv::Op::OpConstant, bound, result_type)};
     op->Add(literal);
     return AddDeclaration(op);
 }
 
 Ref Module::ConstantComposite(Ref result_type, const std::vector<Ref>& constituents) {
-    Op* op{new Op(spv::Op::OpConstantComposite, bound, result_type)};
+    auto const op{new Op(spv::Op::OpConstantComposite, bound, result_type)};
     op->Add(constituents);
     return AddDeclaration(op);
 }
@@ -34,7 +34,7 @@ Ref Module::ConstantSampler(Ref result_type, spv::SamplerAddressingMode addressi
                             bool normalized, spv::SamplerFilterMode filter_mode) {
     AddCapability(spv::Capability::LiteralSampler);
     AddCapability(spv::Capability::Kernel);
-    Op* op{new Op(spv::Op::OpConstantSampler, bound, result_type)};
+    auto const op{new Op(spv::Op::OpConstantSampler, bound, result_type)};
     AddEnum(op, addressing_mode);
     op->Add(normalized ? 1 : 0);
     AddEnum(op, filter_mode);
diff --git a/src/insts/debug.cpp b/src/insts/debug.cpp
index 5e7ea0f..974dde1 100644
--- a/src/insts/debug.cpp
+++ b/src/insts/debug.cpp
@@ -10,7 +10,7 @@
 namespace Sirit {
 
 Ref Module::Name(Ref target, const std::string& name) {
-    Op* op{new Op(spv::Op::OpName)};
+    auto const op{new Op(spv::Op::OpName)};
     op->Add(target);
     op->Add(name);
     debug.push_back(std::unique_ptr<Op>(op));
diff --git a/src/insts/flow.cpp b/src/insts/flow.cpp
index d559fe1..9f0fbb4 100644
--- a/src/insts/flow.cpp
+++ b/src/insts/flow.cpp
@@ -11,7 +11,7 @@ namespace Sirit {
 
 Ref Module::LoopMerge(Ref merge_block, Ref continue_target, spv::LoopControlMask loop_control,
                       const std::vector<Ref>& literals) {
-    Op* op{new Op(spv::Op::OpLoopMerge)};
+    auto const op{new Op(spv::Op::OpLoopMerge)};
     op->Add(merge_block);
     op->Add(continue_target);
     AddEnum(op, loop_control);
@@ -20,7 +20,7 @@ Ref Module::LoopMerge(Ref merge_block, Ref continue_target, spv::LoopControlMask
 }
 
 Ref Module::SelectionMerge(Ref merge_block, spv::SelectionControlMask selection_control) {
-    Op* op{new Op(spv::Op::OpSelectionMerge)};
+    auto const op{new Op(spv::Op::OpSelectionMerge)};
     op->Add(merge_block);
     AddEnum(op, selection_control);
     return AddCode(op);
@@ -31,14 +31,14 @@ Ref Module::Label() {
 }
 
 Ref Module::Branch(Ref target_label) {
-    Op* op{new Op(spv::Op::OpBranch)};
+    auto const op{new Op(spv::Op::OpBranch)};
     op->Add(target_label);
     return AddCode(op);
 }
 
 Ref Module::BranchConditional(Ref condition, Ref true_label, Ref false_label,
                               std::uint32_t true_weight, std::uint32_t false_weight) {
-    Op* op{new Op(spv::Op::OpBranchConditional)};
+    auto const op{new Op(spv::Op::OpBranchConditional)};
     op->Add(condition);
     op->Add(true_label);
     op->Add(false_label);
diff --git a/src/insts/function.cpp b/src/insts/function.cpp
index 210832e..f49ea99 100644
--- a/src/insts/function.cpp
+++ b/src/insts/function.cpp
@@ -10,7 +10,7 @@
 namespace Sirit {
 
 Ref Module::Function(Ref result_type, spv::FunctionControlMask function_control, Ref function_type) {
-    Op* op{new Op{spv::Op::OpFunction, bound++, result_type}};
+    auto const op{new Op{spv::Op::OpFunction, bound++, result_type}};
     op->Add(static_cast<u32>(function_control));
     op->Add(function_type);
     return AddCode(op);
diff --git a/src/insts/type.cpp b/src/insts/type.cpp
index a3cde94..c9ada14 100644
--- a/src/insts/type.cpp
+++ b/src/insts/type.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <cassert>
+#include <optional>
 #include "sirit/sirit.h"
 #include "insts.h"
 
@@ -26,7 +27,7 @@ Ref Module::TypeInt(int width, bool is_signed) {
     } else if (width == 64) {
         AddCapability(spv::Capability::Int64);
     }
-    Op* op{new Op(spv::Op::OpTypeInt, bound)};
+    auto const op{new Op(spv::Op::OpTypeInt, bound)};
     op->Add(width);
     op->Add(is_signed ? 1 : 0);
     return AddDeclaration(op);
@@ -38,14 +39,14 @@ Ref Module::TypeFloat(int width) {
     } else if (width == 64) {
         AddCapability(spv::Capability::Float64);
     }
-    Op* op{new Op(spv::Op::OpTypeFloat, bound)};
+    auto const op{new Op(spv::Op::OpTypeFloat, bound)};
     op->Add(width);
     return AddDeclaration(op);
 }
 
 Ref Module::TypeVector(Ref component_type, int component_count) {
     assert(component_count >= 2);
-    Op* op{new Op(spv::Op::OpTypeVector, bound)};
+    auto const op{new Op(spv::Op::OpTypeVector, bound)};
     op->Add(component_type);
     op->Add(component_count);
     return AddDeclaration(op);
@@ -61,8 +62,8 @@ Ref Module::TypeMatrix(Ref column_type, int column_count) {
 }
 
 Ref Module::TypeImage(Ref sampled_type, spv::Dim dim, int depth, bool arrayed, bool ms,
-                            int sampled, spv::ImageFormat image_format,
-                            spv::AccessQualifier access_qualifier) {
+                      int sampled, spv::ImageFormat image_format,
+                      std::optional<spv::AccessQualifier> access_qualifier) {
     switch (dim) {
         case spv::Dim::Dim1D:
             AddCapability(spv::Capability::Sampled1D);
@@ -123,7 +124,7 @@ Ref Module::TypeImage(Ref sampled_type, spv::Dim dim, int depth, bool arrayed, b
             AddCapability(spv::Capability::StorageImageExtendedFormats);
             break;
     }
-    Op* op{new Op(spv::Op::OpTypeImage, bound)};
+    auto const op{new Op(spv::Op::OpTypeImage, bound)};
     op->Add(sampled_type);
     op->Add(static_cast<u32>(dim));
     op->Add(depth);
@@ -131,9 +132,9 @@ Ref Module::TypeImage(Ref sampled_type, spv::Dim dim, int depth, bool arrayed, b
     op->Add(ms ? 1 : 0);
     op->Add(sampled);
     op->Add(static_cast<u32>(image_format));
-    if (static_cast<u32>(access_qualifier) != Undefined) {
+    if (access_qualifier.has_value()) {
         AddCapability(spv::Capability::Kernel);
-        op->Add(static_cast<u32>(access_qualifier));
+        op->Add(static_cast<u32>(access_qualifier.value()));
     }
     return AddDeclaration(op);
 }
@@ -143,13 +144,13 @@ Ref Module::TypeSampler() {
 }
 
 Ref Module::TypeSampledImage(Ref image_type) {
-    Op* op{new Op(spv::Op::OpTypeSampledImage, bound)};
+    auto const op{new Op(spv::Op::OpTypeSampledImage, bound)};
     op->Add(image_type);
     return AddDeclaration(op);
 }
 
 Ref Module::TypeArray(Ref element_type, Ref length) {
-    Op* op{new Op(spv::Op::OpTypeArray, bound)};
+    auto const op{new Op(spv::Op::OpTypeArray, bound)};
     op->Add(element_type);
     op->Add(length);
     return AddDeclaration(op);
@@ -157,20 +158,20 @@ Ref Module::TypeArray(Ref element_type, Ref length) {
 
 Ref Module::TypeRuntimeArray(Ref element_type) {
     AddCapability(spv::Capability::Shader);
-    Op* op{new Op(spv::Op::OpTypeRuntimeArray, bound)};
+    auto const op{new Op(spv::Op::OpTypeRuntimeArray, bound)};
     op->Add(element_type);
     return AddDeclaration(op);
 }
 
 Ref Module::TypeStruct(const std::vector<Ref>& members) {
-    Op* op{new Op(spv::Op::OpTypeStruct, bound)};
+    auto const op{new Op(spv::Op::OpTypeStruct, bound)};
     op->Add(members);
     return AddDeclaration(op);
 }
 
 Ref Module::TypeOpaque(const std::string& name) {
     AddCapability(spv::Capability::Kernel);
-    Op* op{new Op(spv::Op::OpTypeOpaque, bound)};
+    auto const op{new Op(spv::Op::OpTypeOpaque, bound)};
     op->Add(name);
     return AddDeclaration(op);
 }
@@ -191,14 +192,14 @@ Ref Module::TypePointer(spv::StorageClass storage_class, Ref type) {
             AddCapability(spv::Capability::AtomicStorage);
             break;
     }
-    Op* op{new Op(spv::Op::OpTypePointer, bound)};
+    auto const op{new Op(spv::Op::OpTypePointer, bound)};
     op->Add(static_cast<u32>(storage_class));
     op->Add(type);
     return AddDeclaration(op);
 }
 
 Ref Module::TypeFunction(Ref return_type, const std::vector<Ref>& arguments) {
-    Op* op{new Op(spv::Op::OpTypeFunction, bound)};
+    auto const op{new Op(spv::Op::OpTypeFunction, bound)};
     op->Add(return_type);
     op->Add(arguments);
     return AddDeclaration(op);
@@ -226,7 +227,7 @@ Ref Module::TypeQueue() {
 
 Ref Module::TypePipe(spv::AccessQualifier access_qualifier) {
     AddCapability(spv::Capability::Pipes);
-    Op* op{new Op(spv::Op::OpTypePipe, bound)};
+    auto const op{new Op(spv::Op::OpTypePipe, bound)};
     op->Add(static_cast<u32>(access_qualifier));
     return AddDeclaration(op);
 }
diff --git a/src/literal.cpp b/src/literal.cpp
index a36824c..b1e29bc 100644
--- a/src/literal.cpp
+++ b/src/literal.cpp
@@ -4,35 +4,23 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "sirit/sirit.h"
 #include "common_types.h"
-#include "operand.h"
 #include "lnumber.h"
+#include "operand.h"
+#include "sirit/sirit.h"
 
 namespace Sirit {
 
-Operand* Module::Literal(u32 value) {
-    return new LiteralNumber(value);
-}
+#define DEFINE_LITERAL(type)                                                   \
+    Operand* Module::Literal(type value) {                                     \
+        return LiteralNumber::Create<type>(value);                             \
+    }
 
-Operand* Module::Literal(u64 value) {
-    return new LiteralNumber(value);
-}
-
-Operand* Module::Literal(s32 value) {
-    return new LiteralNumber(value);
-}
-
-Operand* Module::Literal(s64 value) {
-    return new LiteralNumber(value);
-}
-
-Operand* Module::Literal(f32 value) {
-    return new LiteralNumber(value);
-}
-
-Operand* Module::Literal(f64 value) {
-    return new LiteralNumber(value);
-}
+DEFINE_LITERAL(u32)
+DEFINE_LITERAL(u64)
+DEFINE_LITERAL(s32)
+DEFINE_LITERAL(s64)
+DEFINE_LITERAL(f32)
+DEFINE_LITERAL(f64)
 
 } // namespace Sirit
diff --git a/src/lnumber.cpp b/src/lnumber.cpp
index 9c347b0..e7f79f1 100644
--- a/src/lnumber.cpp
+++ b/src/lnumber.cpp
@@ -4,79 +4,26 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include <cassert>
 #include "lnumber.h"
+#include <cassert>
 
 namespace Sirit {
 
-LiteralNumber::LiteralNumber() {
+LiteralNumber::LiteralNumber(std::type_index type) : type(type) {
     operand_type = OperandType::Number;
 }
 
-LiteralNumber::LiteralNumber(u32 number)
-    : uint32(number), type(NumberType::U32) {
-    LiteralNumber();
-}
-
-LiteralNumber::LiteralNumber(s32 number)
-    : int32(number), type(NumberType::S32) {
-    LiteralNumber();
-}
-
-LiteralNumber::LiteralNumber(f32 number)
-    : float32(number), type(NumberType::F32) {
-    LiteralNumber();
-}
-
-LiteralNumber::LiteralNumber(u64 number)
-    : uint64(number), type(NumberType::U64) {
-    LiteralNumber();
-}
-
-LiteralNumber::LiteralNumber(s64 number)
-    : int64(number), type(NumberType::S64) {
-    LiteralNumber();
-}
-
-LiteralNumber::LiteralNumber(f64 number)
-    : float64(number), type(NumberType::F64) {
-    LiteralNumber();
-}
-
 LiteralNumber::~LiteralNumber() = default;
 
 void LiteralNumber::Fetch(Stream& stream) const {
-    switch (type) {
-        case NumberType::S32:
-        case NumberType::U32:
-        case NumberType::F32:
-            stream.Write(uint32);
-            break;
-        case NumberType::S64:
-        case NumberType::U64:
-        case NumberType::F64:
-            stream.Write(uint64);
-            break;
-        default:
-            assert(0);
+    if (is_32) {
+        stream.Write(static_cast<u32>(raw));
+    } else {
+        stream.Write(raw);
     }
 }
 
-u16 LiteralNumber::GetWordCount() const {
-    switch (type) {
-        case NumberType::S32:
-        case NumberType::U32:
-        case NumberType::F32:
-            return 1;
-        case NumberType::S64:
-        case NumberType::U64:
-        case NumberType::F64:
-            return 2;
-        default:
-            assert(0);
-            return 0;
-    }
-}
+u16 LiteralNumber::GetWordCount() const { return is_32 ? 1 : 2; }
 
 bool LiteralNumber::operator==(const Operand& other) const {
     if (operand_type == other.GetType()) {
diff --git a/src/lnumber.h b/src/lnumber.h
index 6b86504..8beb169 100644
--- a/src/lnumber.h
+++ b/src/lnumber.h
@@ -6,19 +6,15 @@
 
 #pragma once
 
-#include "stream.h"
 #include "operand.h"
- 
+#include "stream.h"
+#include <typeindex>
+
 namespace Sirit {
 
 class LiteralNumber : public Operand {
-public:
-    LiteralNumber(u32 number);
-    LiteralNumber(s32 number);
-    LiteralNumber(f32 number);
-    LiteralNumber(u64 number);
-    LiteralNumber(s64 number);
-    LiteralNumber(f64 number);
+  public:
+    LiteralNumber(std::type_index type);
     ~LiteralNumber();
 
     virtual void Fetch(Stream& stream) const;
@@ -26,27 +22,21 @@ public:
 
     virtual bool operator==(const Operand& other) const;
 
-private:
-    LiteralNumber();
+    template <typename T> static LiteralNumber* Create(T value) {
+        static_assert(sizeof(T) == 4 || sizeof(T) == 8);
+        LiteralNumber* number = new LiteralNumber(std::type_index(typeid(T)));
+        if (number->is_32 = sizeof(T) == 4; number->is_32) {
+            number->raw = *reinterpret_cast<u32*>(&value);
+        } else {
+            number->raw = *reinterpret_cast<u64*>(&value);
+        }
+        return number;
+    }
 
-    enum class NumberType {
-        U32,
-        S32,
-        F32,
-        U64,
-        S64,
-        F64
-    } type;
-
-    union {
-        u64 raw{};
-        u32 uint32;
-        s32 int32;
-        u64 uint64;
-        s64 int64;
-        f32 float32;
-        f64 float64;
-    };
+  private:
+    std::type_index type;
+    bool is_32;
+    u64 raw;
 };
 
 } // namespace Sirit
diff --git a/src/lstring.cpp b/src/lstring.cpp
index d15d933..3843a9a 100644
--- a/src/lstring.cpp
+++ b/src/lstring.cpp
@@ -8,8 +8,7 @@
 
 namespace Sirit {
 
-LiteralString::LiteralString(const std::string& string_)
-    : string(string_) {
+LiteralString::LiteralString(const std::string& string_) : string(string_) {
     operand_type = OperandType::String;
 }
 
diff --git a/src/lstring.h b/src/lstring.h
index ea54e23..76fd75b 100644
--- a/src/lstring.h
+++ b/src/lstring.h
@@ -6,14 +6,14 @@
 
 #pragma once
 
-#include <string>
-#include "stream.h"
 #include "operand.h"
+#include "stream.h"
+#include <string>
 
 namespace Sirit {
 
 class LiteralString : public Operand {
-public:
+  public:
     LiteralString(const std::string& string);
     ~LiteralString();
 
@@ -22,7 +22,7 @@ public:
 
     virtual bool operator==(const Operand& other) const;
 
-private:
+  private:
     std::string string;
 };
 
diff --git a/src/op.cpp b/src/op.cpp
index 40ce310..41929bf 100644
--- a/src/op.cpp
+++ b/src/op.cpp
@@ -5,29 +5,28 @@
  */
 
 #include <cassert>
+
 #include "common_types.h"
-#include "operand.h"
-#include "op.h"
 #include "lnumber.h"
 #include "lstring.h"
+#include "op.h"
+#include "operand.h"
 
 namespace Sirit {
 
-Op::Op(spv::Op opcode_, u32 id_, Ref result_type_) 
-    : opcode(opcode_), id(id_), result_type(result_type_) {
+Op::Op(spv::Op opcode, std::optional<u32> id, Ref result_type)
+    : opcode(opcode), id(id), result_type(result_type) {
     operand_type = OperandType::Op;
 }
 
 Op::~Op() = default;
 
 void Op::Fetch(Stream& stream) const {
-    assert(id != UINT32_MAX);
-    stream.Write(id);
+    assert(id.has_value());
+    stream.Write(id.value());
 }
 
-u16 Op::GetWordCount() const {
-    return 1;
-}
+u16 Op::GetWordCount() const { return 1; }
 
 bool Op::operator==(const Operand& other) const {
     if (operand_type != other.GetType()) {
@@ -53,8 +52,8 @@ void Op::Write(Stream& stream) const {
     if (result_type) {
         result_type->Fetch(stream);
     }
-    if (id != UINT32_MAX) {
-        stream.Write(id);
+    if (id.has_value()) {
+        stream.Write(id.value());
     }
     for (const Operand* operand : operands) {
         operand->Fetch(stream);
@@ -66,17 +65,11 @@ void Op::Add(Operand* operand) {
     operand_store.push_back(std::unique_ptr<Operand>(operand));
 }
 
-void Op::Add(const Operand* operand) {
-    operands.push_back(operand);
-}
+void Op::Add(const Operand* operand) { operands.push_back(operand); }
 
-void Op::Add(u32 integer) {
-    Add(new LiteralNumber(integer));
-}
+void Op::Add(u32 integer) { Add(LiteralNumber::Create<u32>(integer)); }
 
-void Op::Add(const std::string& string) {
-    Add(new LiteralString(string));
-}
+void Op::Add(const std::string& string) { Add(new LiteralString(string)); }
 
 void Op::Add(const std::vector<Ref>& ids) {
     for (Ref op : ids) {
@@ -89,7 +82,7 @@ u16 Op::WordCount() const {
     if (result_type) {
         count++;
     }
-    if (id != UINT32_MAX) {
+    if (id.has_value()) {
         count++;
     }
     for (const Operand* operand : operands) {
diff --git a/src/op.h b/src/op.h
index 45d62f9..2a2294d 100644
--- a/src/op.h
+++ b/src/op.h
@@ -6,16 +6,18 @@
 
 #pragma once
 
-#include "sirit/sirit.h"
 #include "common_types.h"
 #include "operand.h"
+#include "sirit/sirit.h"
 #include "stream.h"
+#include <optional>
 
 namespace Sirit {
 
 class Op : public Operand {
-public:
-    explicit Op(spv::Op opcode, u32 id = UINT32_MAX, Ref result_type = nullptr);
+  public:
+    explicit Op(spv::Op opcode, std::optional<u32> id = {},
+                Ref result_type = nullptr);
     ~Op();
 
     virtual void Fetch(Stream& stream) const;
@@ -34,15 +36,15 @@ public:
     void Add(const std::string& string);
 
     void Add(const std::vector<Ref>& ids);
- 
-private:
+
+  private:
     u16 WordCount() const;
 
     spv::Op opcode;
 
     Ref result_type;
 
-    u32 id;
+    std::optional<u32> id;
 
     std::vector<const Operand*> operands;
 
diff --git a/src/operand.cpp b/src/operand.cpp
index b2ed322..44648c3 100644
--- a/src/operand.cpp
+++ b/src/operand.cpp
@@ -4,8 +4,8 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include <cassert>
 #include "operand.h"
+#include <cassert>
 
 namespace Sirit {
 
@@ -22,16 +22,12 @@ u16 Operand::GetWordCount() const {
     return 0;
 }
 
-bool Operand::operator==(const Operand& other) const {
-    return false;
-}
+bool Operand::operator==(const Operand& other) const { return false; }
 
 bool Operand::operator!=(const Operand& other) const {
     return !(*this == other);
 }
 
-OperandType Operand::GetType() const {
-    return operand_type;
-}
+OperandType Operand::GetType() const { return operand_type; }
 
 } // namespace Sirit
diff --git a/src/operand.h b/src/operand.h
index 2583f76..ee9aa81 100644
--- a/src/operand.h
+++ b/src/operand.h
@@ -10,15 +10,10 @@
 
 namespace Sirit {
 
-enum class OperandType {
-    Invalid,
-    Op,
-    Number,
-    String
-};
+enum class OperandType { Invalid, Op, Number, String };
 
 class Operand {
-public:
+  public:
     Operand();
     virtual ~Operand();
 
@@ -30,7 +25,7 @@ public:
 
     OperandType GetType() const;
 
-protected:
+  protected:
     OperandType operand_type{};
 };
 
diff --git a/src/sirit.cpp b/src/sirit.cpp
index 7f01cb6..3d73399 100644
--- a/src/sirit.cpp
+++ b/src/sirit.cpp
@@ -4,17 +4,17 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include <algorithm>
-#include <cassert>
 #include "sirit/sirit.h"
 #include "common_types.h"
 #include "op.h"
 #include "stream.h"
+#include <algorithm>
+#include <cassert>
 
 namespace Sirit {
 
-template<typename T>
-inline void WriteEnum(Stream& stream, spv::Op opcode, T value) {
+template <typename T>
+static void WriteEnum(Stream& stream, spv::Op opcode, T value) {
     Op op{opcode};
     op.Add(static_cast<u32>(value));
     op.Write(stream);
@@ -30,7 +30,7 @@ std::vector<u8> Module::Assemble() const {
 
     stream.Write(spv::MagicNumber);
     stream.Write(spv::Version);
-    stream.Write(GeneratorMagicNumber);
+    stream.Write(GENERATOR_MAGIC_NUMBER);
     stream.Write(bound);
     stream.Write(static_cast<u32>(0));
 
@@ -69,21 +69,22 @@ std::vector<u8> Module::Assemble() const {
     return bytes;
 }
 
-void Module::Optimize(int level) {
-}
+void Module::Optimize(int level) {}
 
 void Module::AddCapability(spv::Capability capability) {
     capabilities.insert(capability);
 }
 
-void Module::SetMemoryModel(spv::AddressingModel addressing_model, spv::MemoryModel memory_model) {
+void Module::SetMemoryModel(spv::AddressingModel addressing_model,
+                            spv::MemoryModel memory_model) {
     this->addressing_model = addressing_model;
     this->memory_model = memory_model;
 }
 
 void Module::AddEntryPoint(spv::ExecutionModel execution_model, Ref entry_point,
-                           const std::string& name, const std::vector<Ref>& interfaces) {
-    Op* op{new Op(spv::Op::OpEntryPoint)};
+                           const std::string& name,
+                           const std::vector<Ref>& interfaces) {
+    auto const op{new Op(spv::Op::OpEntryPoint)};
     op->Add(static_cast<u32>(execution_model));
     op->Add(entry_point);
     op->Add(name);
@@ -102,14 +103,14 @@ Ref Module::AddCode(Op* op) {
     return op;
 }
 
-Ref Module::AddCode(spv::Op opcode, u32 id) {
-    return AddCode(new Op{opcode, id});
+Ref Module::AddCode(spv::Op opcode, std::optional<u32> id) {
+    return AddCode(new Op(opcode, id));
 }
 
 Ref Module::AddDeclaration(Op* op) {
-    const auto& found{std::find_if(declarations.begin(), declarations.end(), [=](const auto& other) {
-        return *other == *op;
-    })};
+    const auto& found{
+        std::find_if(declarations.begin(), declarations.end(),
+                     [&op](const auto& other) { return *other == *op; })};
     if (found != declarations.end()) {
         delete op;
         return found->get();
diff --git a/src/stream.cpp b/src/stream.cpp
index a1144aa..8bfdf65 100644
--- a/src/stream.cpp
+++ b/src/stream.cpp
@@ -8,42 +8,39 @@
 
 namespace Sirit {
 
-Stream::Stream(std::vector<u8>& bytes_)
-    : bytes(bytes_) {}
+Stream::Stream(std::vector<u8>& bytes_) : bytes(bytes_) {}
 
 Stream::~Stream() = default;
 
 void Stream::Write(std::string string) {
-    std::size_t size{string.size()};
-    u8* data{reinterpret_cast<u8*>(string.data())};
-    for (std::size_t i{}; i < size; i++) {
+    const auto size{string.size()};
+    const auto data{reinterpret_cast<u8*>(string.data())};
+    for (std::size_t i = 0; i < size; i++) {
         Write(data[i]);
     }
-    for (std::size_t i{}; i < 4 - size % 4; i++) {
+    for (std::size_t i = 0; i < 4 - size % 4; i++) {
         Write(static_cast<u8>(0));
     }
 }
 
 void Stream::Write(u64 value) {
-    u32* mem{reinterpret_cast<u32*>(&value)};
+    const auto mem{reinterpret_cast<u32*>(&value)};
     Write(mem[0]);
     Write(mem[1]);
 }
 
 void Stream::Write(u32 value) {
-    u16* mem{reinterpret_cast<u16*>(&value)};
+    const auto mem{reinterpret_cast<u16*>(&value)};
     Write(mem[0]);
     Write(mem[1]);
 }
 
 void Stream::Write(u16 value) {
-    u8* mem{reinterpret_cast<u8*>(&value)};
+    const auto mem{reinterpret_cast<u8*>(&value)};
     Write(mem[0]);
     Write(mem[1]);
 }
 
-void Stream::Write(u8 value) {
-    bytes.push_back(value);
-}
+void Stream::Write(u8 value) { bytes.push_back(value); }
 
 } // namespace Sirit
diff --git a/src/stream.h b/src/stream.h
index a87676d..4eec9bf 100644
--- a/src/stream.h
+++ b/src/stream.h
@@ -6,17 +6,17 @@
 
 #pragma once
 
+#include "common_types.h"
 #include <string>
 #include <vector>
-#include "common_types.h"
 
 namespace Sirit {
 
 class Stream {
-public:
+  public:
     explicit Stream(std::vector<u8>& bytes);
     ~Stream();
-    
+
     void Write(std::string string);
 
     void Write(u64 value);
@@ -27,7 +27,7 @@ public:
 
     void Write(u8 value);
 
-private:
+  private:
     std::vector<u8>& bytes;
 };