From 1089b51b66954547aa75317b31723b0877e05dbf Mon Sep 17 00:00:00 2001
From: Peter Sobot <psobot@spotify.com>
Date: Wed, 9 Feb 2022 10:54:52 -0500
Subject: [PATCH] Remove usage of std::variant, which fails on older macOS.

---
 pedalboard/plugin_templates/Resample.h | 75 ++++++++++++++++++++++----
 1 file changed, 65 insertions(+), 10 deletions(-)

diff --git a/pedalboard/plugin_templates/Resample.h b/pedalboard/plugin_templates/Resample.h
index 96ce5f48..4c6e1aba 100644
--- a/pedalboard/plugin_templates/Resample.h
+++ b/pedalboard/plugin_templates/Resample.h
@@ -71,23 +71,78 @@ class VariableQualityResampler {
   }
 
   float getBaseLatency() const {
-    return std::visit([](auto &&i) -> float { return i.getBaseLatency(); },
-                      interpolator);
+    // Unfortunately, std::visit cannot be used here due to macOS version
+    // issues: https://stackoverflow.com/q/52310835/679081
+    if (auto *i =
+            std::get_if<juce::Interpolators::ZeroOrderHold>(&interpolator)) {
+      return i->getBaseLatency();
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Linear>(&interpolator)) {
+      return i->getBaseLatency();
+    } else if (auto *i = std::get_if<juce::Interpolators::CatmullRom>(
+                   &interpolator)) {
+      return i->getBaseLatency();
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Lagrange>(&interpolator)) {
+      return i->getBaseLatency();
+    } else if (auto *i = std::get_if<juce::Interpolators::WindowedSinc>(
+                   &interpolator)) {
+      return i->getBaseLatency();
+    } else {
+      throw std::runtime_error("Unknown resampler quality!");
+    }
   }
 
   void reset() noexcept {
-    std::visit([](auto &&i) { return i.reset(); }, interpolator);
+    // Unfortunately, std::visit cannot be used here due to macOS version
+    // issues: https://stackoverflow.com/q/52310835/679081
+    if (auto *i =
+            std::get_if<juce::Interpolators::ZeroOrderHold>(&interpolator)) {
+      i->reset();
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Linear>(&interpolator)) {
+      i->reset();
+    } else if (auto *i = std::get_if<juce::Interpolators::CatmullRom>(
+                   &interpolator)) {
+      i->reset();
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Lagrange>(&interpolator)) {
+      i->reset();
+    } else if (auto *i = std::get_if<juce::Interpolators::WindowedSinc>(
+                   &interpolator)) {
+      i->reset();
+    } else {
+      throw std::runtime_error("Unknown resampler quality!");
+    }
   }
 
   int process(double speedRatio, const float *inputSamples,
               float *outputSamples, int numOutputSamplesToProduce) noexcept {
-    return std::visit(
-        [speedRatio, inputSamples, outputSamples,
-         numOutputSamplesToProduce](auto &&i) -> float {
-          return i.process(speedRatio, inputSamples, outputSamples,
-                           numOutputSamplesToProduce);
-        },
-        interpolator);
+    // Unfortunately, std::visit cannot be used here due to macOS version
+    // issues: https://stackoverflow.com/q/52310835/679081
+    if (auto *i =
+            std::get_if<juce::Interpolators::ZeroOrderHold>(&interpolator)) {
+      return i->process(speedRatio, inputSamples, outputSamples,
+                        numOutputSamplesToProduce);
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Linear>(&interpolator)) {
+      return i->process(speedRatio, inputSamples, outputSamples,
+                        numOutputSamplesToProduce);
+    } else if (auto *i = std::get_if<juce::Interpolators::CatmullRom>(
+                   &interpolator)) {
+      return i->process(speedRatio, inputSamples, outputSamples,
+                        numOutputSamplesToProduce);
+    } else if (auto *i =
+                   std::get_if<juce::Interpolators::Lagrange>(&interpolator)) {
+      return i->process(speedRatio, inputSamples, outputSamples,
+                        numOutputSamplesToProduce);
+    } else if (auto *i = std::get_if<juce::Interpolators::WindowedSinc>(
+                   &interpolator)) {
+      return i->process(speedRatio, inputSamples, outputSamples,
+                        numOutputSamplesToProduce);
+    } else {
+      throw std::runtime_error("Unknown resampler quality!");
+    }
   }
 
 private: