Use std::optional to express functions that may not return a value

include/SFML/Audio/Music.hpp

@@ -213,10 +213,10 @@ class SFML_AUDIO_API Music : public SoundStream
  /// the seek position for a loop. We then determine whether we are looping on a
  /// loop point or the end-of-file, perform the seek, and return the new position.
  ///
- /// \return The seek position after looping (or -1 if there's no loop)
+ /// \return The seek position after looping (or std::nullopt if there's no loop)
  ///
  ////////////////////////////////////////////////////////////
- std::int64_t onLoop() override;
+ std::optional<std::uint64_t> onLoop() override;
 
 private:
  ////////////////////////////////////////////////////////////

include/SFML/Audio/SoundStream.hpp

@@ -35,6 +35,7 @@
 #include <SFML/System/Time.hpp>
 
 #include <memory>
+#include <optional>
 #include <vector>
 
 #include <cstddef>
@@ -194,9 +195,6 @@ class SFML_AUDIO_API SoundStream : public SoundSource
  bool getLoop() const;
 
 protected:
- // NOLINTNEXTLINE(readability-identifier-naming)
- static constexpr std::int64_t NoLoop = -1; //!< "Invalid" onLoop return value, telling us to continue uninterrupted
-
  ////////////////////////////////////////////////////////////
  /// \brief Default constructor
  ///
@@ -259,10 +257,10 @@ class SFML_AUDIO_API SoundStream : public SoundSource
  /// allow implementation of custom loop points. Otherwise,
  /// it just calls onSeek(Time::Zero) and returns 0.
  ///
- /// \return The seek position after looping (or -1 if there's no loop)
+ /// \return The seek position after looping (or std::nullopt if there's no loop)
  ///
  ////////////////////////////////////////////////////////////
- virtual std::int64_t onLoop();
+ virtual std::optional<std::uint64_t> onLoop();
 
 private:
  ////////////////////////////////////////////////////////////

src/SFML/Audio/Music.cpp

@@ -204,7 +204,7 @@ void Music::onSeek(Time timeOffset)
 
 
 ////////////////////////////////////////////////////////////
-std::int64_t Music::onLoop()
+std::optional<std::uint64_t> Music::onLoop()
 {
  // Called by underlying SoundStream so we can determine where to loop.
  const std::lock_guard lock(m_mutex);
@@ -222,7 +222,7 @@ std::int64_t Music::onLoop()
  m_file.seek(0);
  return 0;
  }
- return NoLoop;
+ return std::nullopt;
 }
 
 

src/SFML/Audio/SoundStream.cpp

@@ -158,10 +158,10 @@ struct SoundStream::Impl
  // If we are looping and at the end of the loop, set the cursor back to the beginning of the loop
  if (!impl.streaming && impl.loop)
  {
- if (const auto seekPositionAfterLoop = owner->onLoop(); seekPositionAfterLoop != NoLoop)
+ if (const auto seekPositionAfterLoop = owner->onLoop())
  {
  impl.streaming = true;
- impl.samplesProcessed = static_cast<std::uint64_t>(seekPositionAfterLoop);
+ impl.samplesProcessed = *seekPositionAfterLoop;
  }
  }
  }
@@ -396,7 +396,7 @@ bool SoundStream::getLoop() const
 
 
 ////////////////////////////////////////////////////////////
-std::int64_t SoundStream::onLoop()
+std::optional<std::uint64_t> SoundStream::onLoop()
 {
  onSeek(Time::Zero);
  return 0;