From 2bf472988bd6ba1cdb2b5339a29e75bc92720b20 Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Thu, 19 Dec 2019 09:27:30 +0100
Subject: [PATCH] We can now use std::exchange() as we switched to C++17

---
 src/libslic3r/ElephantFootCompensation.cpp | 8 ++++----
 src/libslic3r/Utils.hpp                    | 8 --------
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/src/libslic3r/ElephantFootCompensation.cpp b/src/libslic3r/ElephantFootCompensation.cpp
index 69a20b5ec..2694b5e8a 100644
--- a/src/libslic3r/ElephantFootCompensation.cpp
+++ b/src/libslic3r/ElephantFootCompensation.cpp
@@ -472,7 +472,7 @@ static inline void smooth_compensation_banded(const Points &contour, float band,
 			float	l2    = (pthis - pprev).squaredNorm();
 			if (l2 < dist_min2) {
 				float l = sqrt(l2);
-				int jprev = exchange(j, prev_idx_modulo(j, contour));
+				int jprev = std::exchange(j, prev_idx_modulo(j, contour));
 				while (j != i) {
 					const Vec2f pp = contour[j].cast<float>();
 					const float lthis = (pp - pprev).norm();
@@ -487,7 +487,7 @@ static inline void smooth_compensation_banded(const Points &contour, float band,
 					prev  = use_min ? std::min(prev, compensation[j]) : compensation[j];
 					pprev = pp;
 					l     = lnext;
-					jprev = exchange(j, prev_idx_modulo(j, contour));
+					jprev = std::exchange(j, prev_idx_modulo(j, contour));
 				}
 			}
 
@@ -497,7 +497,7 @@ static inline void smooth_compensation_banded(const Points &contour, float band,
 			l2 = (pprev - pthis).squaredNorm();
 			if (l2 < dist_min2) {
 				float l = sqrt(l2);
-				int jprev = exchange(j, next_idx_modulo(j, contour));
+				int jprev = std::exchange(j, next_idx_modulo(j, contour));
 				while (j != i) {
 					const Vec2f pp = contour[j].cast<float>();
 					const float lthis = (pp - pprev).norm();
@@ -512,7 +512,7 @@ static inline void smooth_compensation_banded(const Points &contour, float band,
 					next  = use_min ? std::min(next, compensation[j]) : compensation[j];
 					pprev = pp;
 					l     = lnext;
-					jprev = exchange(j, next_idx_modulo(j, contour));
+					jprev = std::exchange(j, next_idx_modulo(j, contour));
 				}
 			}
 
diff --git a/src/libslic3r/Utils.hpp b/src/libslic3r/Utils.hpp
index e5fae485a..f825f65e5 100644
--- a/src/libslic3r/Utils.hpp
+++ b/src/libslic3r/Utils.hpp
@@ -217,14 +217,6 @@ inline typename CONTAINER_TYPE::value_type& next_value_modulo(typename CONTAINER
 	return container[next_idx_modulo(idx, container.size())];
 }
 
-template<class T, class U = T>
-inline T exchange(T& obj, U&& new_value)
-{
-    T old_value = std::move(obj);
-    obj = std::forward<U>(new_value);
-    return old_value;
-}
-
 extern std::string xml_escape(std::string text);