diff --git a/CMakeLists.txt b/CMakeLists.txt
index 047041f..3b0574f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,7 +17,7 @@ if (NOT CMAKE_BUILD_TYPE)
 endif()
 
 # Set hard requirements for C++
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
diff --git a/include/sirit/sirit.h b/include/sirit/sirit.h
index 5d90b33..3d47d93 100644
--- a/include/sirit/sirit.h
+++ b/include/sirit/sirit.h
@@ -6,13 +6,16 @@
 
 #pragma once
 
+#include <array>
 #include <cstdint>
 #include <memory>
 #include <optional>
+#include <span>
 #include <string>
 #include <unordered_set>
 #include <variant>
 #include <vector>
+
 #include <spirv/unified1/spirv.hpp11>
 
 namespace Sirit {
@@ -50,23 +53,25 @@ public:
 
     /// Adds an entry point.
     void AddEntryPoint(spv::ExecutionModel execution_model, Id entry_point, std::string name,
-                       const std::vector<Id>& interfaces = {});
+                       std::span<const Id> interfaces = {});
 
     /// Adds an entry point.
     template <typename... Ts>
     void AddEntryPoint(spv::ExecutionModel execution_model, Id entry_point, std::string name,
                        Ts&&... interfaces) {
-        AddEntryPoint(execution_model, std::move(entry_point), name, {interfaces...});
+        AddEntryPoint(execution_model, std::move(entry_point), name,
+                      std::span<const Id>{std::array{interfaces...}});
     }
 
     /// Declare an execution mode for an entry point.
     void AddExecutionMode(Id entry_point, spv::ExecutionMode mode,
-                          const std::vector<Literal>& literals = {});
+                          std::span<const Literal> literals = {});
 
     /// Declare an execution mode for an entry point.
     template <typename... Ts>
     void AddExecutionMode(Id entry_point, spv::ExecutionMode mode, Ts&&... literals) {
-        AddExecutionMode(entry_point, mode, {literals...});
+        const Literal stack_literals[] = {std::forward<Ts>(literals)...};
+        AddExecutionMode(entry_point, mode, std::span<const Literal>{stack_literals});
     }
 
     /**
@@ -136,12 +141,12 @@ public:
     Id TypeRuntimeArray(Id element_type);
 
     /// Returns type struct.
-    Id TypeStruct(const std::vector<Id>& members = {});
+    Id TypeStruct(std::span<const Id> members = {});
 
     /// Returns type struct.
     template <typename... Ts>
     Id TypeStruct(Ts&&... members) {
-        return TypeStruct({members...});
+        return TypeStruct(std::span<const Id>{std::array{members...}});
     }
 
     /// Returns type opaque.
@@ -151,12 +156,12 @@ public:
     Id TypePointer(spv::StorageClass storage_class, Id type);
 
     /// Returns type function.
-    Id TypeFunction(Id return_type, const std::vector<Id>& arguments = {});
+    Id TypeFunction(Id return_type, std::span<const Id> arguments = {});
 
     /// Returns type function.
     template <typename... Ts>
     Id TypeFunction(Id return_type, Ts&&... arguments) {
-        return OpTypeFunction(return_type, {arguments...});
+        return TypeFunction(return_type, std::span<const Id>{std::array{arguments...}});
     }
 
     /// Returns type event.
@@ -186,12 +191,12 @@ public:
     Id Constant(Id result_type, const Literal& literal);
 
     /// Returns a numeric scalar constant.
-    Id ConstantComposite(Id result_type, const std::vector<Id>& constituents);
+    Id ConstantComposite(Id result_type, std::span<const Id> constituents);
 
     /// Returns a numeric scalar constant.
     template <typename... Ts>
     Id ConstantComposite(Id result_type, Ts&&... constituents) {
-        return ConstantComposite(result_type, {constituents...});
+        return ConstantComposite(result_type, std::span<const Id>{std::array{constituents...}});
     }
 
     /// Returns a sampler constant.
@@ -210,25 +215,26 @@ public:
     Id OpFunctionEnd();
 
     /// Call a function.
-    Id OpFunctionCall(Id result_type, Id function, const std::vector<Id>& arguments = {});
+    Id OpFunctionCall(Id result_type, Id function, std::span<const Id> arguments = {});
 
     /// Call a function.
     template <typename... Ts>
     Id OpFunctionCall(Id result_type, Id function, Ts&&... arguments) {
-        return OpFunctionCall(result_type, function, {arguments...});
+        return OpFunctionCall(result_type, function, std::span<const Id>{std::array{arguments...}});
     }
 
     // Flow
 
     /// Declare a structured loop.
     Id OpLoopMerge(Id merge_block, Id continue_target, spv::LoopControlMask loop_control,
-                   const std::vector<Id>& literals = {});
+                   std::span<const Id> literals = {});
 
     /// Declare a structured loop.
     template <typename... Ts>
     Id OpLoopMerge(Id merge_block, Id continue_target, spv::LoopControlMask loop_control,
                    Ts&&... literals) {
-        return OpLoopMerge(merge_block, continue_target, loop_control, {literals...});
+        return OpLoopMerge(merge_block, continue_target, loop_control,
+                           std::span<const Id>{std::array{literals...}});
     }
 
     /// Declare a structured selection.
@@ -251,8 +257,8 @@ public:
                            std::uint32_t true_weight = 0, std::uint32_t false_weight = 0);
 
     /// Multi-way branch to one of the operand label.
-    Id OpSwitch(Id selector, Id default_label, const std::vector<Literal>& literals,
-                const std::vector<Id>& labels);
+    Id OpSwitch(Id selector, Id default_label, std::span<const Literal> literals,
+                std::span<const Id> labels);
 
     /// Returns with no value from a function with void return type.
     Id OpReturn();
@@ -284,7 +290,8 @@ public:
     /// Allocate an object in memory, resulting in a copy to it.
     Id OpVariable(Id result_type, spv::StorageClass storage_class, Id initializer = nullptr);
 
-    /// Form a pointer to a texel of an image. Use of such a pointer is limited to atomic operations.
+    /// Form a pointer to a texel of an image. Use of such a pointer is limited to atomic
+    /// operations.
     Id OpImageTexelPointer(Id result_type, Id image, Id coordinate, Id sample);
 
     /// Load through a pointer.
@@ -294,12 +301,12 @@ public:
     Id OpStore(Id pointer, Id object, std::optional<spv::MemoryAccessMask> memory_access = {});
 
     /// Create a pointer into a composite object that can be used with OpLoad and OpStore.
-    Id OpAccessChain(Id result_type, Id base, const std::vector<Id>& indexes = {});
+    Id OpAccessChain(Id result_type, Id base, std::span<const Id> indexes = {});
 
     /// Create a pointer into a composite object that can be used with OpLoad and OpStore.
     template <typename... Ts>
     Id OpAccessChain(Id result_type, Id base, Ts&&... indexes) {
-        return OpAccessChain(result_type, base, {indexes...});
+        return OpAccessChain(result_type, base, std::span<const Id>{std::array{indexes...}});
     }
 
     /// Extract a single, dynamically selected, component of a vector.
@@ -310,50 +317,56 @@ public:
 
     /// Make a copy of a composite object, while modifying one part of it.
     Id OpCompositeInsert(Id result_type, Id object, Id composite,
-                         const std::vector<Literal>& indexes = {});
+                         std::span<const Literal> indexes = {});
 
     /// Make a copy of a composite object, while modifying one part of it.
     template <typename... Ts>
     Id OpCompositeInsert(Id result_type, Id object, Id composite, Ts&&... indexes) {
-        return OpCompositeInsert(result_type, object, composite, {indexes...});
+        const Literal stack_indexes[] = {std::forward<Ts>(indexes)...};
+        return OpCompositeInsert(result_type, object, composite,
+                                 std::span<const Literal>{stack_indexes});
     }
 
     /// Extract a part of a composite object.
-    Id OpCompositeExtract(Id result_type, Id composite, const std::vector<Literal>& indexes = {});
+    Id OpCompositeExtract(Id result_type, Id composite, std::span<const Literal> indexes = {});
 
     /// Extract a part of a composite object.
     template <typename... Ts>
     Id OpCompositeExtract(Id result_type, Id composite, Ts&&... indexes) {
-        return OpCompositeExtract(result_type, composite, {indexes...});
+        const Literal stack_indexes[] = {std::forward<Ts>(indexes)...};
+        return OpCompositeExtract(result_type, composite, std::span<const Literal>{stack_indexes});
     }
 
     /// Construct a new composite object from a set of constituent objects that will fully form it.
-    Id OpCompositeConstruct(Id result_type, const std::vector<Id>& ids);
+    Id OpCompositeConstruct(Id result_type, std::span<const Id> ids);
 
     /// Construct a new composite object from a set of constituent objects that will fully form it.
     template <typename... Ts>
     Id OpCompositeConstruct(Id result_type, Ts&&... ids) {
-        return OpCompositeConstruct(result_type, {ids...});
+        return OpCompositeConstruct(result_type, std::span<const Id>{std::array{ids...}});
     }
 
     // Annotation
 
     /// Add a decoration to target.
-    Id Decorate(Id target, spv::Decoration decoration, const std::vector<Literal>& literals = {});
+    Id Decorate(Id target, spv::Decoration decoration, std::span<const Literal> literals = {});
 
     /// Add a decoration to target.
     template <typename... Ts>
     Id Decorate(Id target, spv::Decoration decoration, Ts&&... literals) {
-        return Decorate(target, decoration, {literals...});
+        const Literal stack_literals[] = {std::forward<Ts>(literals)...};
+        return Decorate(target, decoration, std::span<const Literal>{stack_literals});
     }
 
     Id MemberDecorate(Id structure_type, Literal member, spv::Decoration decoration,
-                      const std::vector<Literal>& literals = {});
+                      std::span<const Literal> literals = {});
 
     template <typename... Ts>
     Id MemberDecorate(Id structure_type, Literal member, spv::Decoration decoration,
                       Ts&&... literals) {
-        return MemberDecorate(structure_type, member, decoration, {literals...});
+        const Literal stack_literals[] = {std::forward<Ts>(literals)...};
+        return MemberDecorate(structure_type, member, decoration,
+                              std::span<const Literal>{stack_literals});
     }
 
     // Misc
@@ -608,13 +621,13 @@ public:
     // Extensions
 
     /// Execute an instruction in an imported set of extended instructions.
-    Id OpExtInst(Id result_type, Id set, std::uint32_t instruction,
-                 const std::vector<Id>& operands);
+    Id OpExtInst(Id result_type, Id set, std::uint32_t instruction, std::span<const Id> operands);
 
     /// Execute an instruction in an imported set of extended instructions.
     template <typename... Ts>
     Id OpExtInst(Id result_type, Id set, std::uint32_t instruction, Ts&&... operands) {
-        return OpExtInst(result_type, set, instruction, {operands...});
+        return OpExtInst(result_type, set, instruction,
+                         std::span<const Id>{std::array{operands...}});
     }
 
     /// Result is x if x >= 0; otherwise result is -x.
@@ -764,86 +777,88 @@ public:
     /// Sample an image with an implicit level of detail.
     Id OpImageSampleImplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                 std::optional<spv::ImageOperandsMask> image_operands = {},
-                                const std::vector<Id>& operands = {});
+                                std::span<const Id> operands = {});
 
     /// Sample an image with an implicit level of detail.
     template <typename... Ts>
     Id OpImageSampleImplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                 spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleImplicitLod(result_type, sampled_image, coordinate, image_operands,
-                                        {operands...});
+                                        std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image using an explicit level of detail.
     Id OpImageSampleExplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                 spv::ImageOperandsMask image_operands,
-                                const std::vector<Id>& operands = {});
+                                std::span<const Id> operands = {});
 
     /// Sample an image using an explicit level of detail.
     template <typename... Ts>
     Id OpImageSampleExplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                 spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleExplicitLod(result_type, sampled_image, coordinate, image_operands,
-                                        {operands...});
+                                        std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image doing depth-comparison with an implicit level of detail.
     Id OpImageSampleDrefImplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                     std::optional<spv::ImageOperandsMask> image_operands = {},
-                                    const std::vector<Id>& operands = {});
+                                    std::span<const Id> operands = {});
 
     /// Sample an image doing depth-comparison with an implicit level of detail.
     template <typename... Ts>
     Id OpImageSampleDrefImplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                     spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleDrefImplicitLod(result_type, sampled_image, coordinate, dref,
-                                            image_operands, {operands...});
+                                            image_operands,
+                                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image doing depth-comparison using an explicit level of detail.
     Id OpImageSampleDrefExplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                     spv::ImageOperandsMask image_operands,
-                                    const std::vector<Id>& operands = {});
+                                    std::span<const Id> operands = {});
 
     /// Sample an image doing depth-comparison using an explicit level of detail.
     template <typename... Ts>
     Id OpImageSampleDrefExplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                     spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleDrefExplicitLod(result_type, sampled_image, coordinate, dref,
-                                            image_operands, {operands...});
+                                            image_operands,
+                                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image with with a project coordinate and an implicit level of detail.
     Id OpImageSampleProjImplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                     std::optional<spv::ImageOperandsMask> image_operands = {},
-                                    const std::vector<Id>& operands = {});
+                                    std::span<const Id> operands = {});
 
     /// Sample an image with with a project coordinate and an implicit level of detail.
     template <typename... Ts>
     Id OpImageSampleProjImplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                     spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleProjImplicitLod(result_type, sampled_image, coordinate, image_operands,
-                                            {operands...});
+                                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image with a project coordinate using an explicit level of detail.
     Id OpImageSampleProjExplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                     spv::ImageOperandsMask image_operands,
-                                    const std::vector<Id>& operands = {});
+                                    std::span<const Id> operands = {});
 
     /// Sample an image with a project coordinate using an explicit level of detail.
     template <typename... Ts>
     Id OpImageSampleProjExplicitLod(Id result_type, Id sampled_image, Id coordinate,
                                     spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleProjExplicitLod(result_type, sampled_image, coordinate, image_operands,
-                                            {operands...});
+                                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image with a project coordinate, doing depth-comparison, with an implicit level of
     /// detail.
     Id OpImageSampleProjDrefImplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                         std::optional<spv::ImageOperandsMask> image_operands = {},
-                                        const std::vector<Id>& operands = {});
+                                        std::span<const Id> operands = {});
 
     /// Sample an image with a project coordinate, doing depth-comparison, with an implicit level of
     /// detail.
@@ -851,14 +866,15 @@ public:
     Id OpImageSampleProjDrefImplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                         spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleProjDrefImplicitLod(result_type, sampled_image, coordinate, dref,
-                                                image_operands, {operands...});
+                                                image_operands,
+                                                std::span<const Id>{std::array{operands...}});
     }
 
     /// Sample an image with a project coordinate, doing depth-comparison, using an explicit level
     /// of detail.
     Id OpImageSampleProjDrefExplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                         spv::ImageOperandsMask image_operands,
-                                        const std::vector<Id>& operands = {});
+                                        std::span<const Id> operands = {});
 
     /// Sample an image with a project coordinate, doing depth-comparison, using an explicit level
     /// of detail.
@@ -866,69 +882,73 @@ public:
     Id OpImageSampleProjDrefExplicitLod(Id result_type, Id sampled_image, Id coordinate, Id dref,
                                         spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageSampleProjDrefExplicitLod(result_type, sampled_image, coordinate, dref,
-                                                image_operands, {operands...});
+                                                image_operands,
+                                                std::span<const Id>{std::array{operands...}});
     }
 
     /// Fetch a single texel from an image whose Sampled operand is 1.
     Id OpImageFetch(Id result_type, Id sampled_image, Id coordinate,
                     std::optional<spv::ImageOperandsMask> image_operands = {},
-                    const std::vector<Id>& operands = {});
+                    std::span<const Id> operands = {});
 
     /// Fetch a single texel from an image whose Sampled operand is 1.
     template <typename... Ts>
     Id OpImageFetch(Id result_type, Id sampled_image, Id coordinate,
                     spv::ImageOperandsMask image_operands, Ts&&... operands) {
-        return OpImageFetch(result_type, sampled_image, coordinate, image_operands, {operands...});
+        return OpImageFetch(result_type, sampled_image, coordinate, image_operands,
+                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Gathers the requested component from four texels.
     Id OpImageGather(Id result_type, Id sampled_image, Id coordinate, Id component,
                      std::optional<spv::ImageOperandsMask> image_operands = {},
-                     const std::vector<Id>& operands = {});
+                     std::span<const Id> operands = {});
 
     /// Gathers the requested component from four texels.
     template <typename... Ts>
     Id OpImageGather(Id result_type, Id sampled_image, Id coordinate, Id component,
                      spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageGather(result_type, sampled_image, coordinate, component, image_operands,
-                             {operands...});
+                             std::span<const Id>{std::array{operands...}});
     }
 
     /// Gathers the requested depth-comparison from four texels.
     Id OpImageDrefGather(Id result_type, Id sampled_image, Id coordinate, Id dref,
                          std::optional<spv::ImageOperandsMask> image_operands = {},
-                         const std::vector<Id>& operands = {});
+                         std::span<const Id> operands = {});
 
     /// Gathers the requested depth-comparison from four texels.
     template <typename... Ts>
     Id OpImageDrefGather(Id result_type, Id sampled_image, Id coordinate, Id dref,
                          spv::ImageOperandsMask image_operands, Ts&&... operands) {
         return OpImageDrefGather(result_type, sampled_image, coordinate, dref, image_operands,
-                                 {operands...});
+                                 std::span<const Id>{std::array{operands...}});
     }
 
     /// Read a texel from an image without a sampler.
     Id OpImageRead(Id result_type, Id sampled_image, Id coordinate,
                    std::optional<spv::ImageOperandsMask> image_operands = {},
-                   const std::vector<Id>& operands = {});
+                   std::span<const Id> operands = {});
 
     /// Read a texel from an image without a sampler.
     template <typename... Ts>
     Id OpImageRead(Id result_type, Id sampled_image, Id coordinate,
                    spv::ImageOperandsMask image_operands, Ts&&... operands) {
-        return OpImageRead(result_type, sampled_image, coordinate, image_operands, {operands...});
+        return OpImageRead(result_type, sampled_image, coordinate, image_operands,
+                           std::span<const Id>{std::array{operands...}});
     }
 
     /// Write a texel to an image without a sampler.
     Id OpImageWrite(Id image, Id coordinate, Id texel,
                     std::optional<spv::ImageOperandsMask> image_operands = {},
-                    const std::vector<Id>& operands = {});
+                    std::span<const Id> operands = {});
 
     /// Write a texel to an image without a sampler.
     template <typename... Ts>
     Id OpImageWrite(Id image, Id coordinate, Id texel, spv::ImageOperandsMask image_operands,
                     Ts&&... operands) {
-        return OpImageWrite(image, coordinate, texel, image_operands, {operands...});
+        return OpImageWrite(image, coordinate, texel, image_operands,
+                            std::span<const Id>{std::array{operands...}});
     }
 
     /// Extract the image from a sampled image.
diff --git a/src/instructions/annotation.cpp b/src/instructions/annotation.cpp
index da79684..cbe4343 100644
--- a/src/instructions/annotation.cpp
+++ b/src/instructions/annotation.cpp
@@ -12,7 +12,7 @@
 
 namespace Sirit {
 
-Id Module::Decorate(Id target, spv::Decoration decoration, const std::vector<Literal>& literals) {
+Id Module::Decorate(Id target, spv::Decoration decoration, std::span<const Literal> literals) {
     auto op{std::make_unique<Op>(spv::Op::OpDecorate)};
     op->Add(target);
     op->Add(static_cast<u32>(decoration));
@@ -22,7 +22,7 @@ Id Module::Decorate(Id target, spv::Decoration decoration, const std::vector<Lit
 }
 
 Id Module::MemberDecorate(Id structure_type, Literal member, spv::Decoration decoration,
-                          const std::vector<Literal>& literals) {
+                          std::span<const Literal> literals) {
     auto op{std::make_unique<Op>(spv::Op::OpMemberDecorate)};
     op->Add(structure_type);
     op->Add(member);
diff --git a/src/instructions/constant.cpp b/src/instructions/constant.cpp
index 1d50327..25b0fa5 100644
--- a/src/instructions/constant.cpp
+++ b/src/instructions/constant.cpp
@@ -24,7 +24,7 @@ Id Module::Constant(Id result_type, const Literal& literal) {
     return AddDeclaration(std::move(op));
 }
 
-Id Module::ConstantComposite(Id result_type, const std::vector<Id>& constituents) {
+Id Module::ConstantComposite(Id result_type, std::span<const Id> constituents) {
     auto op{std::make_unique<Op>(spv::Op::OpConstantComposite, bound, result_type)};
     op->Add(constituents);
     return AddDeclaration(std::move(op));
diff --git a/src/instructions/extension.cpp b/src/instructions/extension.cpp
index a806347..332d972 100644
--- a/src/instructions/extension.cpp
+++ b/src/instructions/extension.cpp
@@ -12,7 +12,7 @@
 
 namespace Sirit {
 
-Id Module::OpExtInst(Id result_type, Id set, u32 instruction, const std::vector<Id>& operands) {
+Id Module::OpExtInst(Id result_type, Id set, u32 instruction, std::span<const Id> operands) {
     auto op{std::make_unique<Op>(spv::Op::OpExtInst, bound++, result_type)};
     op->Add(set);
     op->Add(instruction);
diff --git a/src/instructions/flow.cpp b/src/instructions/flow.cpp
index ccec4bf..2520e6c 100644
--- a/src/instructions/flow.cpp
+++ b/src/instructions/flow.cpp
@@ -13,7 +13,7 @@
 namespace Sirit {
 
 Id Module::OpLoopMerge(Id merge_block, Id continue_target, spv::LoopControlMask loop_control,
-                       const std::vector<Id>& literals) {
+                       std::span<const Id> literals) {
     auto op{std::make_unique<Op>(spv::Op::OpLoopMerge)};
     op->Add(merge_block);
     op->Add(continue_target);
@@ -52,8 +52,8 @@ Id Module::OpBranchConditional(Id condition, Id true_label, Id false_label, u32
     return AddCode(std::move(op));
 }
 
-Id Module::OpSwitch(Id selector, Id default_label, const std::vector<Literal>& literals,
-                    const std::vector<Id>& labels) {
+Id Module::OpSwitch(Id selector, Id default_label, std::span<const Literal> literals,
+                    std::span<const Id> labels) {
     const std::size_t size = literals.size();
     assert(literals.size() == labels.size());
     auto op{std::make_unique<Op>(spv::Op::OpSwitch)};
diff --git a/src/instructions/function.cpp b/src/instructions/function.cpp
index 3fb1126..f5982e8 100644
--- a/src/instructions/function.cpp
+++ b/src/instructions/function.cpp
@@ -21,7 +21,7 @@ Id Module::OpFunctionEnd() {
     return AddCode(spv::Op::OpFunctionEnd);
 }
 
-Id Module::OpFunctionCall(Id result_type, Id function, const std::vector<Id>& arguments) {
+Id Module::OpFunctionCall(Id result_type, Id function, std::span<const Id> arguments) {
     auto op{std::make_unique<Op>(spv::Op::OpFunctionCall, bound++, result_type)};
     op->Add(function);
     op->Add(arguments);
diff --git a/src/instructions/image.cpp b/src/instructions/image.cpp
index d12dc2c..7db8f1c 100644
--- a/src/instructions/image.cpp
+++ b/src/instructions/image.cpp
@@ -11,7 +11,7 @@
 namespace Sirit {
 
 static void AddImageOperands(Op* op, std::optional<spv::ImageOperandsMask> image_operands,
-                             const std::vector<Id>& operands) {
+                             std::span<const Id> operands) {
     if (!image_operands)
         return;
     op->Add(static_cast<u32>(*image_operands));
@@ -21,7 +21,7 @@ static void AddImageOperands(Op* op, std::optional<spv::ImageOperandsMask> image
 #define DEFINE_IMAGE_OP(opcode)                                                                    \
     Id Module::opcode(Id result_type, Id sampled_image, Id coordinate,                             \
                       std::optional<spv::ImageOperandsMask> image_operands,                        \
-                      const std::vector<Id>& operands) {                                           \
+                      std::span<const Id> operands) {                                              \
         auto op{std::make_unique<Op>(spv::Op::opcode, bound++, result_type)};                      \
         op->Add(sampled_image);                                                                    \
         op->Add(coordinate);                                                                       \
@@ -31,7 +31,7 @@ static void AddImageOperands(Op* op, std::optional<spv::ImageOperandsMask> image
 
 #define DEFINE_IMAGE_EXP_OP(opcode)                                                                \
     Id Module::opcode(Id result_type, Id sampled_image, Id coordinate,                             \
-                      spv::ImageOperandsMask image_operands, const std::vector<Id>& operands) {    \
+                      spv::ImageOperandsMask image_operands, std::span<const Id> operands) {       \
         auto op{std::make_unique<Op>(spv::Op::opcode, bound++, result_type)};                      \
         op->Add(sampled_image);                                                                    \
         op->Add(coordinate);                                                                       \
@@ -43,7 +43,7 @@ static void AddImageOperands(Op* op, std::optional<spv::ImageOperandsMask> image
 #define DEFINE_IMAGE_EXTRA_OP(opcode)                                                              \
     Id Module::opcode(Id result_type, Id sampled_image, Id coordinate, Id extra,                   \
                       std::optional<spv::ImageOperandsMask> image_operands,                        \
-                      const std::vector<Id>& operands) {                                           \
+                      std::span<const Id> operands) {                                              \
         auto op{std::make_unique<Op>(spv::Op::opcode, bound++, result_type)};                      \
         op->Add(sampled_image);                                                                    \
         op->Add(coordinate);                                                                       \
@@ -54,7 +54,7 @@ static void AddImageOperands(Op* op, std::optional<spv::ImageOperandsMask> image
 
 #define DEFINE_IMAGE_EXTRA_EXP_OP(opcode)                                                          \
     Id Module::opcode(Id result_type, Id sampled_image, Id coordinate, Id extra,                   \
-                      spv::ImageOperandsMask image_operands, const std::vector<Id>& operands) {    \
+                      spv::ImageOperandsMask image_operands, std::span<const Id> operands) {       \
         auto op{std::make_unique<Op>(spv::Op::opcode, bound++, result_type)};                      \
         op->Add(sampled_image);                                                                    \
         op->Add(coordinate);                                                                       \
@@ -106,7 +106,7 @@ Id Module::OpSampledImage(Id result_type, Id image, Id sampler) {
 
 Id Module::OpImageWrite(Id image, Id coordinate, Id texel,
                         std::optional<spv::ImageOperandsMask> image_operands,
-                        const std::vector<Id>& operands) {
+                        std::span<const Id> operands) {
     auto op{std::make_unique<Op>(spv::Op::OpImageWrite)};
     op->Add(image);
     op->Add(coordinate);
diff --git a/src/instructions/memory.cpp b/src/instructions/memory.cpp
index 33c8b07..8b3a159 100644
--- a/src/instructions/memory.cpp
+++ b/src/instructions/memory.cpp
@@ -46,7 +46,7 @@ Id Module::OpStore(Id pointer, Id object, std::optional<spv::MemoryAccessMask> m
     return AddCode(std::move(op));
 }
 
-Id Module::OpAccessChain(Id result_type, Id base, const std::vector<Id>& indexes) {
+Id Module::OpAccessChain(Id result_type, Id base, std::span<const Id> indexes) {
     assert(indexes.size() > 0);
     auto op{std::make_unique<Op>(spv::Op::OpAccessChain, bound++, result_type)};
     op->Add(base);
@@ -70,7 +70,7 @@ Id Module::OpVectorInsertDynamic(Id result_type, Id vector, Id component, Id ind
 }
 
 Id Module::OpCompositeInsert(Id result_type, Id object, Id composite,
-                             const std::vector<Literal>& indexes) {
+                             std::span<const Literal> indexes) {
     auto op{std::make_unique<Op>(spv::Op::OpCompositeInsert, bound++, result_type)};
     op->Add(object);
     op->Add(composite);
@@ -78,14 +78,14 @@ Id Module::OpCompositeInsert(Id result_type, Id object, Id composite,
     return AddCode(std::move(op));
 }
 
-Id Module::OpCompositeExtract(Id result_type, Id composite, const std::vector<Literal>& indexes) {
+Id Module::OpCompositeExtract(Id result_type, Id composite, std::span<const Literal> indexes) {
     auto op{std::make_unique<Op>(spv::Op::OpCompositeExtract, bound++, result_type)};
     op->Add(composite);
     op->Add(indexes);
     return AddCode(std::move(op));
 }
 
-Id Module::OpCompositeConstruct(Id result_type, const std::vector<Id>& ids) {
+Id Module::OpCompositeConstruct(Id result_type, std::span<const Id> ids) {
     assert(ids.size() >= 1);
     auto op{std::make_unique<Op>(spv::Op::OpCompositeConstruct, bound++, result_type)};
     op->Add(ids);
diff --git a/src/instructions/type.cpp b/src/instructions/type.cpp
index 2f2b15a..e302cd2 100644
--- a/src/instructions/type.cpp
+++ b/src/instructions/type.cpp
@@ -90,7 +90,7 @@ Id Module::TypeRuntimeArray(Id element_type) {
     return AddDeclaration(std::move(op));
 }
 
-Id Module::TypeStruct(const std::vector<Id>& members) {
+Id Module::TypeStruct(std::span<const Id> members) {
     auto op{std::make_unique<Op>(spv::Op::OpTypeStruct, bound)};
     op->Add(members);
     return AddDeclaration(std::move(op));
@@ -109,7 +109,7 @@ Id Module::TypePointer(spv::StorageClass storage_class, Id type) {
     return AddDeclaration(std::move(op));
 }
 
-Id Module::TypeFunction(Id return_type, const std::vector<Id>& arguments) {
+Id Module::TypeFunction(Id return_type, std::span<const Id> arguments) {
     auto op{std::make_unique<Op>(spv::Op::OpTypeFunction, bound)};
     op->Add(return_type);
     op->Add(arguments);
diff --git a/src/literal_number.cpp b/src/literal_number.cpp
index 3dd8668..a4c436e 100644
--- a/src/literal_number.cpp
+++ b/src/literal_number.cpp
@@ -26,7 +26,7 @@ std::size_t LiteralNumber::GetWordCount() const noexcept {
     return is_32 ? 1 : 2;
 }
 
-bool LiteralNumber::operator==(const Operand& other) const noexcept {
+bool LiteralNumber::Equal(const Operand& other) const noexcept {
     if (!EqualType(other)) {
         return false;
     }
diff --git a/src/literal_number.h b/src/literal_number.h
index 6fd60d1..46d19b0 100644
--- a/src/literal_number.h
+++ b/src/literal_number.h
@@ -24,7 +24,7 @@ public:
 
     std::size_t GetWordCount() const noexcept override;
 
-    bool operator==(const Operand& other) const noexcept override;
+    bool Equal(const Operand& other) const noexcept override;
 
     template <typename T>
     static std::unique_ptr<LiteralNumber> Create(T value) {
diff --git a/src/literal_string.cpp b/src/literal_string.cpp
index b201228..58aa40f 100644
--- a/src/literal_string.cpp
+++ b/src/literal_string.cpp
@@ -23,7 +23,7 @@ std::size_t LiteralString::GetWordCount() const noexcept {
     return string.size() / 4 + 1;
 }
 
-bool LiteralString::operator==(const Operand& other) const noexcept {
+bool LiteralString::Equal(const Operand& other) const noexcept {
     if (!EqualType(other)) {
         return false;
     }
diff --git a/src/literal_string.h b/src/literal_string.h
index 7c051d1..608ac53 100644
--- a/src/literal_string.h
+++ b/src/literal_string.h
@@ -21,7 +21,7 @@ public:
 
     std::size_t GetWordCount() const noexcept override;
 
-    bool operator==(const Operand& other) const noexcept override;
+    bool Equal(const Operand& other) const noexcept override;
 
 private:
     std::string string;
diff --git a/src/op.cpp b/src/op.cpp
index a735519..d8d7ade 100644
--- a/src/op.cpp
+++ b/src/op.cpp
@@ -30,7 +30,7 @@ std::size_t Op::GetWordCount() const noexcept {
     return 1;
 }
 
-bool Op::operator==(const Operand& other) const noexcept {
+bool Op::Equal(const Operand& other) const noexcept {
     if (!EqualType(other)) {
         return false;
     }
@@ -38,7 +38,7 @@ bool Op::operator==(const Operand& other) const noexcept {
     if (op.opcode == opcode && result_type == op.result_type &&
         operands.size() == op.operands.size()) {
         for (std::size_t i = 0; i < operands.size(); i++) {
-            if (*operands[i] != *op.operands[i]) {
+            if (!operands[i]->Equal(*op.operands[i])) {
                 return false;
             }
         }
@@ -89,7 +89,7 @@ void Op::Add(const Literal& literal) {
     }());
 }
 
-void Op::Add(const std::vector<Literal>& literals) {
+void Op::Add(std::span<const Literal> literals) {
     for (const auto& literal : literals) {
         Add(literal);
     }
@@ -112,7 +112,7 @@ void Op::Add(std::string string) {
     Sink(std::make_unique<LiteralString>(std::move(string)));
 }
 
-void Op::Add(const std::vector<Id>& ids) {
+void Op::Add(std::span<const Id> ids) {
     assert(std::all_of(ids.begin(), ids.end(), [](auto id_) { return id_; }));
     operands.insert(operands.end(), ids.begin(), ids.end());
 }
diff --git a/src/op.h b/src/op.h
index cc16ac3..276bfc9 100644
--- a/src/op.h
+++ b/src/op.h
@@ -26,7 +26,7 @@ public:
 
     std::size_t GetWordCount() const noexcept override;
 
-    bool operator==(const Operand& other) const noexcept override;
+    bool Equal(const Operand& other) const noexcept override;
 
     void Write(Stream& stream) const;
 
@@ -34,7 +34,7 @@ public:
 
     void Add(const Literal& literal);
 
-    void Add(const std::vector<Literal>& literals);
+    void Add(std::span<const Literal> literals);
 
     void Add(const Operand* operand);
 
@@ -44,7 +44,7 @@ public:
 
     void Add(std::string string);
 
-    void Add(const std::vector<Id>& ids);
+    void Add(std::span<const Id> ids);
 
 private:
     u16 CalculateTotalWords() const noexcept;
diff --git a/src/operand.h b/src/operand.h
index 4e19f80..90b11f1 100644
--- a/src/operand.h
+++ b/src/operand.h
@@ -23,11 +23,7 @@ public:
 
     virtual std::size_t GetWordCount() const noexcept = 0;
 
-    virtual bool operator==(const Operand& other) const noexcept = 0;
-
-    bool operator!=(const Operand& other) const noexcept {
-        return !operator==(other);
-    }
+    virtual bool Equal(const Operand& other) const noexcept = 0;
 
     bool EqualType(const Operand& other) const noexcept {
         return operand_type == other.operand_type;
diff --git a/src/sirit.cpp b/src/sirit.cpp
index 473830c..c95634a 100644
--- a/src/sirit.cpp
+++ b/src/sirit.cpp
@@ -74,13 +74,14 @@ 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, Id entry_point,
-                           std::string name, const std::vector<Id>& interfaces) {
+void Module::AddEntryPoint(spv::ExecutionModel execution_model, Id entry_point, std::string name,
+                           std::span<const Id> interfaces) {
     auto op{std::make_unique<Op>(spv::Op::OpEntryPoint)};
     op->Add(static_cast<u32>(execution_model));
     op->Add(entry_point);
@@ -90,7 +91,7 @@ void Module::AddEntryPoint(spv::ExecutionModel execution_model, Id entry_point,
 }
 
 void Module::AddExecutionMode(Id entry_point, spv::ExecutionMode mode,
-                              const std::vector<Literal>& literals) {
+                              std::span<const Literal> literals) {
     auto op{std::make_unique<Op>(spv::Op::OpExecutionMode)};
     op->Add(entry_point);
     op->Add(static_cast<u32>(mode));
@@ -123,14 +124,14 @@ Id Module::AddCode(spv::Op opcode, std::optional<u32> id) {
 }
 
 Id Module::AddDeclaration(std::unique_ptr<Op> op) {
-    const auto& found{std::find_if(declarations.begin(), declarations.end(),
-                                   [&op](const auto& other) { return *other == *op; })};
+    const auto found = std::find_if(declarations.begin(), declarations.end(),
+                                    [&op](const auto& other) { return op->Equal(*other); });
     if (found != declarations.end()) {
         return found->get();
     }
     const auto id = op.get();
     declarations.push_back(std::move(op));
-    bound++;
+    ++bound;
     return id;
 }