From d2a7df6540d899894de54e1a3193a9d5a133fbdb Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Tue, 13 Apr 2021 19:28:53 +0200
Subject: [PATCH] fix: clang compilation fixed

---
 example/kalman_filter/kalman.h                    | 8 ++++++++
 example/kalman_filter/kalman_filter-example_5.cpp | 6 +++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/example/kalman_filter/kalman.h b/example/kalman_filter/kalman.h
index 439dc3a4..48406382 100644
--- a/example/kalman_filter/kalman.h
+++ b/example/kalman_filter/kalman.h
@@ -22,6 +22,7 @@
 
 #pragma once
 
+#include <units/bits/external/hacks.h>
 #include <units/format.h>
 #include <units/generic/dimensionless.h>
 #include <units/isq/dimensions/time.h>
@@ -74,6 +75,13 @@ public:
   uncertainty_type uncertainty;
 };
 
+#if UNITS_COMP_CLANG == 12
+
+template<QuantityOrQuantityPoint QQP, units::Quantity U>
+estimation(state<QQP>, U) -> estimation<QQP>;
+
+#endif
+
 // kalman gain
 template<units::Quantity Q>
 constexpr units::dimensionless<units::one> kalman_gain(Q estimate_uncertainty, Q measurement_uncertainty)
diff --git a/example/kalman_filter/kalman_filter-example_5.cpp b/example/kalman_filter/kalman_filter-example_5.cpp
index b818f19a..cd99ddd6 100644
--- a/example/kalman_filter/kalman_filter-example_5.cpp
+++ b/example/kalman_filter/kalman_filter-example_5.cpp
@@ -63,11 +63,11 @@ int main()
 
   print_header(initial);
   estimation next = predict(initial);
-  for(int index = 1; const auto& m : measurements) {
+  for(int index = 1; const auto& measured : measurements) {
     const auto& previous = next;
     const auto gain = kalman_gain(previous.uncertainty, measurement_uncertainty);
-    const estimation current = update(previous, m, gain);
+    const estimation current = update(previous, measured, gain);
     next = predict(current);
-    print(index++, gain, m, current, next);
+    print(index++, gain, measured, current, next);
   }
 }