From f73de50a0847d346f629bb6b4025fee620376c1a Mon Sep 17 00:00:00 2001
From: James Betker <jbetker@gmail.com>
Date: Sun, 27 Dec 2015 23:59:34 -0600
Subject: [PATCH] Make code useable from C++

---
 gps.h    | 8 ++++++++
 kalman.h | 8 ++++++++
 matrix.h | 8 ++++++++
 3 files changed, 24 insertions(+)

diff --git a/gps.h b/gps.h
index a209df4..25e515d 100644
--- a/gps.h
+++ b/gps.h
@@ -15,6 +15,10 @@
 #include <stdio.h>
 #include "kalman.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
 /* Create a GPS filter that only tracks two dimensions of position and
    velocity.
    The inherent assumption is that changes in velocity are randomly
@@ -56,4 +60,8 @@ double calculate_mph(double lat, double lon,
 /* Extract speed in miles per hour from a velocity2d Kalman filter. */
 double get_mph(KalmanFilter f);
 
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
 #endif
diff --git a/kalman.h b/kalman.h
index d66f96f..2f317bf 100644
--- a/kalman.h
+++ b/kalman.h
@@ -3,6 +3,10 @@
 
 #include "matrix.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
 /* Refer to http://en.wikipedia.org/wiki/Kalman_filter for
    mathematical details. The naming scheme is that variables get names
    that make sense, and are commented with their analog in
@@ -86,4 +90,8 @@ void predict(KalmanFilter f);
 /* Just the estimation phase of update. */
 void estimate(KalmanFilter f);
 
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
 #endif
diff --git a/matrix.h b/matrix.h
index ce4e2fa..050d6a8 100644
--- a/matrix.h
+++ b/matrix.h
@@ -1,6 +1,10 @@
 #ifndef __MATRIX_H__
 #define __MATRIX_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
 typedef struct {
   /* Dimensions */
   int rows;
@@ -73,4 +77,8 @@ void shear_row(Matrix m, int r1, int r2, double scalar);
    input is mutated as well by this routine. */
 int destructive_invert_matrix(Matrix input, Matrix output);
 
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
 #endif