Prefer const references: Beat-Converter does not modify the TempoMap

diff --git a/libs/ardour/ardour/beats_frames_converter.h b/libs/ardour/ardour/beats_frames_converter.h
index f0cd73dc6a6a6c5214dd9e7b8ede1b651a9a208a..19275927a8388b8622d9c04b3f1dd1fec5ed525b 100644 (file)
--- a/libs/ardour/ardour/beats_frames_converter.h
+++ b/libs/ardour/ardour/beats_frames_converter.h
@@ -39,7 +39,7 @@ class TempoMap;
 class LIBARDOUR_API BeatsFramesConverter
        : public Evoral::TimeConverter<Evoral::Beats,framepos_t> {
 public:
-       BeatsFramesConverter (TempoMap& tempo_map, framepos_t origin)
+       BeatsFramesConverter (const TempoMap& tempo_map, framepos_t origin)
                : Evoral::TimeConverter<Evoral::Beats, framepos_t> (origin)
                , _tempo_map(tempo_map)
        {}
@@ -48,7 +48,7 @@ public:
        Evoral::Beats from (framepos_t frames) const;
 
 private:
-       TempoMap& _tempo_map;
+       const TempoMap& _tempo_map;
 };
 
 /** Converter between quarter-note beats and frames.  Takes distances in quarter-note beats or frames
@@ -58,7 +58,7 @@ private:
 class LIBARDOUR_API DoubleBeatsFramesConverter
        : public Evoral::TimeConverter<double,framepos_t> {
 public:
-       DoubleBeatsFramesConverter (TempoMap& tempo_map, framepos_t origin)
+       DoubleBeatsFramesConverter (const TempoMap& tempo_map, framepos_t origin)
                : Evoral::TimeConverter<double, framepos_t> (origin)
                , _tempo_map(tempo_map)
        {}
@@ -67,7 +67,7 @@ public:
        double from (framepos_t frames) const;
 
 private:
-       TempoMap& _tempo_map;
+       const TempoMap& _tempo_map;
 };
 
 } /* namespace ARDOUR */