fix: Refactor

include/c2pa.hpp

@@ -40,6 +40,7 @@
 #include <vector>
 #include <optional>
 #include <memory>
+#include <utility>
 
 #include "c2pa.h"
 
@@ -638,21 +639,17 @@ namespace c2pa
         Reader& operator=(const Reader&) = delete;
 
         Reader(Reader&& other) noexcept
-            : c2pa_reader(other.c2pa_reader),
+            : c2pa_reader(std::exchange(other.c2pa_reader, nullptr)),
               owned_stream(std::move(other.owned_stream)),
               cpp_stream(std::move(other.cpp_stream)) {
-            other.c2pa_reader = nullptr;
         }
 
         Reader& operator=(Reader&& other) noexcept {
             if (this != &other) {
-                if (c2pa_reader != nullptr) {
-                    c2pa_free(c2pa_reader);
-                }
-                c2pa_reader = other.c2pa_reader;
+                c2pa_free(c2pa_reader);
+                c2pa_reader = std::exchange(other.c2pa_reader, nullptr);
                 owned_stream = std::move(other.owned_stream);
                 cpp_stream = std::move(other.cpp_stream);
-                other.c2pa_reader = nullptr;
             }
             return *this;
         }
@@ -754,15 +751,13 @@ namespace c2pa
 
         /// @brief Move constructor.
         /// @param other Signer to move from.
-        Signer(Signer&& other) noexcept : signer(other.signer) {
-            other.signer = nullptr;
+        Signer(Signer&& other) noexcept : signer(std::exchange(other.signer, nullptr)) {
         }
 
         Signer& operator=(Signer&& other) noexcept {
             if (this != &other) {
                 c2pa_free(signer);
-                signer = other.signer;
-                other.signer = nullptr;
+                signer = std::exchange(other.signer, nullptr);
             }
             return *this;
         }
@@ -810,16 +805,13 @@ namespace c2pa
 
         Builder& operator=(const Builder&) = delete;
 
-        Builder(Builder&& other) noexcept : builder(other.builder) {
-            other.builder = nullptr;
+        Builder(Builder&& other) noexcept : builder(std::exchange(other.builder, nullptr)) {
         }
 
         Builder& operator=(Builder&& other) noexcept {
             if (this != &other) {
-                if (builder != nullptr)
-                    c2pa_free(builder);
-                builder = other.builder;
-                other.builder = nullptr;
+                c2pa_free(builder);
+                builder = std::exchange(other.builder, nullptr);
             }
             return *this;
         }

src/c2pa.cpp

@@ -287,10 +287,13 @@ inline std::vector<unsigned char> to_byte_vector(const unsigned char* data, int6
     /// This class is used to throw exceptions for errors encountered by the C2PA library via c2pa_error().
 
     C2paException::C2paException()
+        : message_([]{
+            auto result = c2pa_error();
+            std::string msg = result ? std::string(result) : std::string();
+            c2pa_free(result);
+            return msg;
+        }())
     {
-        auto result = c2pa_error();
-        message_ = result ? std::string(result) : std::string();
-        c2pa_free(result);
     }
 
     C2paException::C2paException(std::string message) : message_(std::move(message))
@@ -378,44 +381,24 @@ inline std::vector<unsigned char> to_byte_vector(const unsigned char* data, int6
         }
     }
 
-    Context::Context(const Settings& settings) : context(nullptr) {
-        if (!settings.is_valid()) {
-            throw C2paException("Settings object is invalid");
-        }
-        auto builder = c2pa_context_builder_new();
-        if (!builder) {
-            throw C2paException("Failed to create Context builder");
-        }
-        if (c2pa_context_builder_set_settings(builder, settings.c_settings()) != 0) {
-            c2pa_free(builder);
-            throw C2paException();
-        }
-        // The C API consumes the builder on build
-        context = c2pa_context_builder_build(builder);
-        if (!context) {
-            throw C2paException("Failed to build context");
-        }
+    Context::Context(const Settings& settings)
+        : Context(ContextBuilder().with_settings(settings).create_context()) {
     }
 
-    Context::Context(Context&& other) noexcept : context(other.context) {
-        other.context = nullptr;
+    Context::Context(Context&& other) noexcept
+        : context(std::exchange(other.context, nullptr)) {
     }
 
     Context& Context::operator=(Context&& other) noexcept {
         if (this != &other) {
-            if (context) {
-                c2pa_free(context);
-            }
-            context = other.context;
-            other.context = nullptr;
+            c2pa_free(context);
+            context = std::exchange(other.context, nullptr);
         }
         return *this;
     }
 
     Context::~Context() noexcept {
-        if (context) {
-            c2pa_free(context);
-        }
+        c2pa_free(context);
     }
 
     C2paContext* Context::c_context() const noexcept {
@@ -443,18 +426,14 @@ inline std::vector<unsigned char> to_byte_vector(const unsigned char* data, int6
 
     Context::ContextBuilder& Context::ContextBuilder::operator=(ContextBuilder&& other) noexcept {
         if (this != &other) {
-            if (context_builder) {
-                c2pa_free(context_builder);
-            }
+            c2pa_free(context_builder);
             context_builder = std::exchange(other.context_builder, nullptr);
         }
         return *this;
     }
 
     Context::ContextBuilder::~ContextBuilder() noexcept {
-        if (context_builder) {
-            c2pa_free(context_builder);
-        }
+        c2pa_free(context_builder);
     }
 
     bool Context::ContextBuilder::is_valid() const noexcept {
@@ -497,7 +476,7 @@ inline std::vector<unsigned char> to_byte_vector(const unsigned char* data, int6
             throw C2paException("ContextBuilder is invalid (moved from)");
         }
 
-        // The C API consumes the builder on build
+        // The C API consumes the context builder on build
         C2paContext* ctx = c2pa_context_builder_build(context_builder);
         if (!ctx) {
             throw C2paException("Failed to build context");