From 3c4f93cf24e513e764b029306080fcdf20d96296 Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lordofhyphens@gmail.com>
Date: Thu, 2 Mar 2017 00:46:20 -0600
Subject: [PATCH] Cpp11 (#3731)

* Enabled c++11 support (required for IO::AMF), extended Travis build to build with g++ 4.9
* ifdef guard in poly2tri/util to avoid redefinition warning
* cache local-lib
---
 .travis.yml                    | 7 ++++++-
 xs/Build.PL                    | 7 ++++++-
 xs/src/poly2tri/common/utils.h | 4 +++-
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 8e9616ab54..2d84fd28df 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,13 +11,18 @@ branches:
     - stable
 sudo: false
 cache:
-    - apt
+  apt: true
+  directories:
+    - local-lib
 addons:
   apt:
     sources:
     - boost-latest
+    - ubuntu-toolchain-r-test
     packages:
     - libboost-thread1.55-dev
     - libboost-system1.55-dev
     - libboost-filesystem1.55-dev
     - liblocal-lib-perl
+    - g++-4.9
+env: CC=g++-4.9
diff --git a/xs/Build.PL b/xs/Build.PL
index deb8dad658..557a5fd451 100644
--- a/xs/Build.PL
+++ b/xs/Build.PL
@@ -15,8 +15,13 @@ my $mswin = $^O eq 'MSWin32';
 # HAS_BOOL         : stops Perl/lib/CORE/handy.h from doing "#  define bool char" for MSVC
 # NOGDI            : prevents inclusion of wingdi.h which defines functions Polygon() and Polyline() in global namespace
 # BOOST_ASIO_DISABLE_KQUEUE : prevents a Boost ASIO bug on OS X: https://svn.boost.org/trac/boost/ticket/5339
+# std=c++11 Enforce usage of C++11 (required now). Minimum compiler supported: gcc 4.9, clang 3.3, MSVC 14.0
 my @cflags = qw(-D_GLIBCXX_USE_C99 -DHAS_BOOL -DNOGDI -DSLIC3RXS -DBOOST_ASIO_DISABLE_KQUEUE
-    -Wno-c++11-extensions);
+    -std=c++11);
+if ($cpp_guess->is_gcc)	{
+	# GCC is pedantic with c++11 std, so undefine strict ansi to get M_PI back
+	push @cflags, qw(-U__STRICT_ANSI__);
+}
 my @ldflags = ();
 if ($^O eq 'darwin') {
     push @ldflags, qw(-framework IOKit -framework CoreFoundation);
diff --git a/xs/src/poly2tri/common/utils.h b/xs/src/poly2tri/common/utils.h
index ffb713f58f..b4dfec4c48 100644
--- a/xs/src/poly2tri/common/utils.h
+++ b/xs/src/poly2tri/common/utils.h
@@ -33,7 +33,9 @@
 #define UTILS_H
 
 // Otherwise #defines like M_PI are undeclared under Visual Studio
+#ifndef _USE_MATH_DEFINES
 #define _USE_MATH_DEFINES
+#endif
 
 #include <exception>
 #include <math.h>
@@ -119,4 +121,4 @@ bool InScanArea(const Point& pa, const Point& pb, const Point& pc, const Point&
 
 }
 
-#endif
\ No newline at end of file
+#endif