Consistently print errors in factory functions

include/SFML/Audio/Music.hpp

@@ -235,7 +235,8 @@ private:
     /// \brief Try opening the music file from an optional input sound file
     ///
     ////////////////////////////////////////////////////////////
-    [[nodiscard]] static std::optional<Music> tryOpenFromFile(std::optional<InputSoundFile>&& optFile);
+    [[nodiscard]] static std::optional<Music> tryOpenFromInputSoundFile(std::optional<InputSoundFile>&& optFile,
+                                                                        const char*                     errorContext);
 
     ////////////////////////////////////////////////////////////
     /// \brief Initialize the internal state after loading a new music

include/SFML/Network/IpAddress.hpp

@@ -56,6 +56,8 @@ public:
     ///
     /// \param address IP address or network name
     ///
+    /// \return Address if provided argument was valid, otherwise `std::nullopt`
+    ///
     ////////////////////////////////////////////////////////////
     [[nodiscard]] static std::optional<IpAddress> resolve(std::string_view address);
 
@@ -128,7 +130,7 @@ public:
     /// Unlike getPublicAddress, this function is fast and may be
     /// used safely anywhere.
     ///
-    /// \return Local IP address of the computer
+    /// \return Local IP address of the computer on success, `std::nullopt` otherwise
     ///
     /// \see getPublicAddress
     ///
@@ -152,7 +154,7 @@ public:
     ///
     /// \param timeout Maximum time to wait
     ///
-    /// \return Public IP address of the computer
+    /// \return Public IP address of the computer on success, `std::nullopt` otherwise
     ///
     /// \see getLocalAddress
     ///

src/SFML/Audio/InputSoundFile.cpp

@@ -34,6 +34,7 @@
 #include <SFML/System/InputStream.hpp>
 #include <SFML/System/MemoryInputStream.hpp>
 #include <SFML/System/Time.hpp>
+#include <SFML/System/Utils.hpp>
 
 #include <ostream>
 #include <utility>
@@ -71,19 +72,32 @@ std::optional<InputSoundFile> InputSoundFile::openFromFile(const std::filesystem
     // Find a suitable reader for the file type
     auto reader = SoundFileFactory::createReaderFromFilename(filename);
     if (!reader)
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     // Wrap the file into a stream
     auto file = std::make_unique<FileInputStream>();
 
     // Open it
     if (!file->open(filename))
+    {
+        err() << "Failed to open input sound file from file (couldn't open file input stream)\n"
+              << formatDebugPathInfo(filename) << std::endl;
+
         return std::nullopt;
+    }
 
     // Pass the stream to the reader
     auto info = reader->open(*file);
     if (!info)
+    {
+        err() << "Failed to open input sound file from file (reader open failure)\n"
+              << formatDebugPathInfo(filename) << std::endl;
+
         return std::nullopt;
+    }
 
     return InputSoundFile(std::move(reader), std::move(file), info->sampleCount, info->sampleRate, std::move(info->channelMap));
 }
@@ -95,7 +109,10 @@ std::optional<InputSoundFile> InputSoundFile::openFromMemory(const void* data, s
     // Find a suitable reader for the file type
     auto reader = SoundFileFactory::createReaderFromMemory(data, sizeInBytes);
     if (!reader)
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     // Wrap the memory file into a stream
     auto memory = std::make_unique<MemoryInputStream>(data, sizeInBytes);
@@ -103,7 +120,10 @@ std::optional<InputSoundFile> InputSoundFile::openFromMemory(const void* data, s
     // Pass the stream to the reader
     auto info = reader->open(*memory);
     if (!info)
+    {
+        err() << "Failed to open input sound file from memory (reader open failure)" << std::endl;
         return std::nullopt;
+    }
 
     return InputSoundFile(std::move(reader), std::move(memory), info->sampleCount, info->sampleRate, std::move(info->channelMap));
 }
@@ -115,7 +135,10 @@ std::optional<InputSoundFile> InputSoundFile::openFromStream(InputStream& stream
     // Find a suitable reader for the file type
     auto reader = SoundFileFactory::createReaderFromStream(stream);
     if (!reader)
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     // Don't forget to reset the stream to its beginning before re-opening it
     if (stream.seek(0) != 0)
@@ -127,7 +150,10 @@ std::optional<InputSoundFile> InputSoundFile::openFromStream(InputStream& stream
     // Pass the stream to the reader
     auto info = reader->open(stream);
     if (!info)
+    {
+        err() << "Failed to open input sound file from stream (reader open failure)" << std::endl;
         return std::nullopt;
+    }
 
     return InputSoundFile(std::move(reader), {&stream, false}, info->sampleCount, info->sampleRate, std::move(info->channelMap));
 }

src/SFML/Audio/Music.cpp

@@ -79,10 +79,13 @@ Music& Music::operator=(Music&&) noexcept = default;
 
 
 ////////////////////////////////////////////////////////////
-std::optional<Music> Music::tryOpenFromFile(std::optional<InputSoundFile>&& optFile)
+std::optional<Music> Music::tryOpenFromInputSoundFile(std::optional<InputSoundFile>&& optFile, const char* errorContext)
 {
     if (!optFile.has_value())
+    {
+        err() << "Failed to open music from " << errorContext << std::endl;
         return std::nullopt;
+    }
 
     // TODO: apply RVO here via passkey idiom
     return Music(std::move(*optFile));
@@ -92,21 +95,21 @@ std::optional<Music> Music::tryOpenFromFile(std::optional<InputSoundFile>&& optF
 ////////////////////////////////////////////////////////////
 std::optional<Music> Music::openFromFile(const std::filesystem::path& filename)
 {
-    return tryOpenFromFile(InputSoundFile::openFromFile(filename));
+    return tryOpenFromInputSoundFile(InputSoundFile::openFromFile(filename), "file");
 }
 
 
 ////////////////////////////////////////////////////////////
 std::optional<Music> Music::openFromMemory(const void* data, std::size_t sizeInBytes)
 {
-    return tryOpenFromFile(InputSoundFile::openFromMemory(data, sizeInBytes));
+    return tryOpenFromInputSoundFile(InputSoundFile::openFromMemory(data, sizeInBytes), "memory");
 }
 
 
 ////////////////////////////////////////////////////////////
 std::optional<Music> Music::openFromStream(InputStream& stream)
 {
-    return tryOpenFromFile(InputSoundFile::openFromStream(stream));
+    return tryOpenFromInputSoundFile(InputSoundFile::openFromStream(stream), "stream");
 }
 
 

src/SFML/Audio/OutputSoundFile.cpp

@@ -29,6 +29,8 @@
 #include <SFML/Audio/SoundFileFactory.hpp>
 #include <SFML/Audio/SoundFileWriter.hpp>
 
+#include <SFML/System/Err.hpp>
+
 #include <cassert>
 
 
@@ -44,11 +46,15 @@ std::optional<OutputSoundFile> OutputSoundFile::openFromFile(
     // Find a suitable writer for the file type
     auto writer = SoundFileFactory::createWriterFromFilename(filename);
     if (!writer)
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     // Pass the stream to the reader
     if (!writer->open(filename, sampleRate, channelCount, channelMap))
     {
+        err() << "Failed to open output sound file from file (writer open failure)" << std::endl;
         return std::nullopt;
     }
 

src/SFML/Audio/SoundBuffer.cpp

@@ -72,8 +72,9 @@ std::optional<SoundBuffer> SoundBuffer::loadFromFile(const std::filesystem::path
 {
     if (auto file = InputSoundFile::openFromFile(filename))
         return initialize(*file);
-    else
+
-        return std::nullopt;
+    err() << "Failed to open sound buffer from file" << std::endl;
+    return std::nullopt;
 }
 
 
@@ -82,8 +83,9 @@ std::optional<SoundBuffer> SoundBuffer::loadFromMemory(const void* data, std::si
 {
     if (auto file = InputSoundFile::openFromMemory(data, sizeInBytes))
         return initialize(*file);
-    else
+
-        return std::nullopt;
+    err() << "Failed to open sound buffer from memory" << std::endl;
+    return std::nullopt;
 }
 
 
@@ -92,8 +94,9 @@ std::optional<SoundBuffer> SoundBuffer::loadFromStream(InputStream& stream)
 {
     if (auto file = InputSoundFile::openFromStream(stream))
         return initialize(*file);
-    else
+
-        return std::nullopt;
+    err() << "Failed to open sound buffer from stream" << std::endl;
+    return std::nullopt;
 }
 
 
@@ -223,7 +226,11 @@ std::optional<SoundBuffer> SoundBuffer::initialize(InputSoundFile& file)
         // Update the internal buffer with the new samples
         SoundBuffer soundBuffer(std::move(samples));
         if (!soundBuffer.update(file.getChannelCount(), file.getSampleRate(), file.getChannelMap()))
+        {
+            err() << "Failed to initialize sound buffer (internal update failure)" << std::endl;
             return std::nullopt;
+        }
+
         return soundBuffer;
     }
     else

src/SFML/Graphics/Texture.cpp

@@ -266,30 +266,33 @@ std::optional<Texture> Texture::create(const Vector2u& size, bool sRgb)
 ////////////////////////////////////////////////////////////
 std::optional<Texture> Texture::loadFromFile(const std::filesystem::path& filename, bool sRgb, const IntRect& area)
 {
-    const auto image = sf::Image::loadFromFile(filename);
+    if (const auto image = sf::Image::loadFromFile(filename))
-    if (!image)
+        return loadFromImage(*image, sRgb, area);
-        return std::nullopt;
+
-    return loadFromImage(*image, sRgb, area);
+    err() << "Failed to load texture from file" << std::endl;
+    return std::nullopt;
 }
 
 
 ////////////////////////////////////////////////////////////
 std::optional<Texture> Texture::loadFromMemory(const void* data, std::size_t size, bool sRgb, const IntRect& area)
 {
-    const auto image = sf::Image::loadFromMemory(data, size);
+    if (const auto image = sf::Image::loadFromMemory(data, size))
-    if (!image)
+        return loadFromImage(*image, sRgb, area);
-        return std::nullopt;
+
-    return loadFromImage(*image, sRgb, area);
+    err() << "Failed to load texture from memory" << std::endl;
+    return std::nullopt;
 }
 
 
 ////////////////////////////////////////////////////////////
 std::optional<Texture> Texture::loadFromStream(InputStream& stream, bool sRgb, const IntRect& area)
 {
-    const auto image = sf::Image::loadFromStream(stream);
+    if (const auto image = sf::Image::loadFromStream(stream))
-    if (!image)
+        return loadFromImage(*image, sRgb, area);
-        return std::nullopt;
+
-    return loadFromImage(*image, sRgb, area);
+    err() << "Failed to load texture from stream" << std::endl;
+    return std::nullopt;
 }
 
 
@@ -307,11 +310,11 @@ std::optional<Texture> Texture::loadFromImage(const Image& image, bool sRgb, con
         if (auto texture = sf::Texture::create(image.getSize(), sRgb))
         {
             texture->update(image);
-
             return texture;
         }
         else
         {
+            // Error message generated in called function.
             return std::nullopt;
         }
     }
@@ -354,6 +357,7 @@ std::optional<Texture> Texture::loadFromImage(const Image& image, bool sRgb, con
         }
         else
         {
+            // Error message generated in called function.
             return std::nullopt;
         }
     }

src/SFML/Network/IpAddress.cpp

@@ -29,6 +29,8 @@
 #include <SFML/Network/IpAddress.hpp>
 #include <SFML/Network/SocketImpl.hpp>
 
+#include <SFML/System/Err.hpp>
+
 #include <istream>
 #include <ostream>
 
@@ -49,7 +51,10 @@ std::optional<IpAddress> IpAddress::resolve(std::string_view address)
     using namespace std::string_view_literals;
 
     if (address.empty())
+    {
+        // Not generating en error message here as resolution failure is a valid outcome.
         return std::nullopt;
+    }
 
     if (address == "255.255.255.255"sv)
     {
@@ -81,6 +86,7 @@ std::optional<IpAddress> IpAddress::resolve(std::string_view address)
         return IpAddress(ntohl(ip));
     }
 
+    // Not generating en error message here as resolution failure is a valid outcome.
     return std::nullopt;
 }
 
@@ -125,13 +131,18 @@ std::optional<IpAddress> IpAddress::getLocalAddress()
     // Create the socket
     const SocketHandle sock = socket(PF_INET, SOCK_DGRAM, 0);
     if (sock == priv::SocketImpl::invalidSocket())
+    {
+        err() << "Failed to retrieve local address (invalid socket)" << std::endl;
         return std::nullopt;
+    }
 
     // Connect the socket to localhost on any port
     sockaddr_in address = priv::SocketImpl::createAddress(ntohl(INADDR_LOOPBACK), 9);
     if (connect(sock, reinterpret_cast<sockaddr*>(&address), sizeof(address)) == -1)
     {
         priv::SocketImpl::close(sock);
+
+        err() << "Failed to retrieve local address (socket connection failure)" << std::endl;
         return std::nullopt;
     }
 
@@ -140,6 +151,8 @@ std::optional<IpAddress> IpAddress::getLocalAddress()
     if (getsockname(sock, reinterpret_cast<sockaddr*>(&address), &size) == -1)
     {
         priv::SocketImpl::close(sock);
+
+        err() << "Failed to retrieve local address (socket local address retrieval failure)" << std::endl;
         return std::nullopt;
     }
 
@@ -163,10 +176,15 @@ std::optional<IpAddress> IpAddress::getPublicAddress(Time timeout)
     Http                 server("www.sfml-dev.org");
     const Http::Request  request("/ip-provider.php", Http::Request::Method::Get);
     const Http::Response page = server.sendRequest(request, timeout);
-    if (page.getStatus() == Http::Response::Status::Ok)
+
+    const Http::Response::Status status = page.getStatus();
+
+    if (status == Http::Response::Status::Ok)
         return IpAddress::resolve(page.getBody());
 
-    // Something failed: return an invalid address
+    err() << "Failed to retrieve public address from external IP resolution server (HTTP response status "
+          << static_cast<int>(status) << ")" << std::endl;
+
     return std::nullopt;
 }
 

src/SFML/Window/Cursor.cpp

@@ -28,9 +28,11 @@
 #include <SFML/Window/Cursor.hpp>
 #include <SFML/Window/CursorImpl.hpp>
 
+#include <SFML/System/Err.hpp>
 #include <SFML/System/Vector2.hpp>
 
 #include <memory>
+#include <ostream>
 
 namespace sf
 {
@@ -57,11 +59,17 @@ Cursor& Cursor::operator=(Cursor&&) noexcept = default;
 std::optional<Cursor> Cursor::loadFromPixels(const std::uint8_t* pixels, Vector2u size, Vector2u hotspot)
 {
     if ((pixels == nullptr) || (size.x == 0) || (size.y == 0))
+    {
+        err() << "Failed to load cursor from pixels (invalid arguments)" << std::endl;
         return std::nullopt;
+    }
 
     Cursor cursor;
     if (!cursor.m_impl->loadFromPixels(pixels, size, hotspot))
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     return cursor;
 }
@@ -72,7 +80,10 @@ std::optional<Cursor> Cursor::loadFromSystem(Type type)
 {
     Cursor cursor;
     if (!cursor.m_impl->loadFromSystem(type))
+    {
+        // Error message generated in called function.
         return std::nullopt;
+    }
 
     return cursor;
 }