From 679a2db566ba29d5acd55af2583ae8c398f07b28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Per=20Gr=C3=B6n?= <per@lumiary.com>
Date: Tue, 7 Feb 2023 16:25:43 +0100
Subject: [PATCH] Make the code build against libc++ on Linux

`defined(__linux__)` does not imply that libstd++ is used.

`#include <math.h>` does not define `std::ceil` in libc++.
---
 src/gausspoint/gpline.h | 2 +-
 src/mesh/gentools.cpp   | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/gausspoint/gpline.h b/src/gausspoint/gpline.h
index f4afd9d6..b284b7d0 100755
--- a/src/gausspoint/gpline.h
+++ b/src/gausspoint/gpline.h
@@ -8,7 +8,7 @@
 #define GPLINE_H
 
 #include <iostream>
-#include <math.h>
+#include <cmath>
 #include <vector>
 #include "gausspoints.h"
 
diff --git a/src/mesh/gentools.cpp b/src/mesh/gentools.cpp
index 2278b707..33d1cba0 100755
--- a/src/mesh/gentools.cpp
+++ b/src/mesh/gentools.cpp
@@ -5,7 +5,7 @@
 #include "lagrangeformfunction.h"
 #include "slmpi.h"
 
-#if defined(__linux__)
+#if defined(__linux__) && !defined(_LIBCPP_VERSION)
 #include <parallel/algorithm>
 #endif
 
@@ -21,7 +21,7 @@ void gentools::stablecoordinatesort(std::vector<double> noisethreshold, std::vec
     std::iota(reorderingvector.begin(), reorderingvector.end(), 0);
     // Sort 'reorderingvector' according to 'coordinates' with x > y > z priority order:
     // The < operator is overloaded by a lambda function.
-    #if defined(__linux__)
+    #if defined(__linux__) && !defined(_LIBCPP_VERSION)
     __gnu_parallel::sort(reorderingvector.begin(), reorderingvector.end(), [&](int elem1, int elem2)
     #else
     std::sort(reorderingvector.begin(), reorderingvector.end(), [&](int elem1, int elem2)
@@ -276,7 +276,7 @@ void gentools::stablesort(std::vector<int>& tosort, std::vector<int>& reordering
     std::iota(reorderingvector.begin(), reorderingvector.end(), 0);
     // Sort 'reorderingvector' according to 'tosort':
     // The < operator is overloaded by a lambda function.
-    #if defined(__linux__)
+    #if defined(__linux__) && !defined(_LIBCPP_VERSION)
     __gnu_parallel::sort(reorderingvector.begin(), reorderingvector.end(), [&](int elem1, int elem2)
     #else
     std::sort(reorderingvector.begin(), reorderingvector.end(), [&](int elem1, int elem2)
@@ -352,7 +352,7 @@ bool sortfun(const std::tuple<int,int,double>& elem1, const std::tuple<int,int,d
 void gentools::tuple3sort(std::vector<std::tuple<int,int,double>>& tosort)
 {
     // Parallel sort on Linux only for now:
-    #if defined(__linux__)
+    #if defined(__linux__) && !defined(_LIBCPP_VERSION)
     __gnu_parallel::sort(tosort.begin(), tosort.end(), sortfun);
     #else
     std::sort(tosort.begin(), tosort.end(), sortfun);