From ee62d39e6f4621c0f137bed91d77318cb3b38bfb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Thu, 5 Jul 2012 21:02:50 +0200
Subject: [PATCH] Initial work for GCC 4.5 compatibility.

GCC 4.5 doesn't know constexpr keyword and nullptr. As all constexpr
functions are here inline, it can be done with a simple macro.
---
 CMakeLists.txt              |  1 +
 src/CMakeLists.txt          |  4 ++++
 src/Math/Math.h             |  1 +
 src/Math/MathTypeTraits.h   |  2 ++
 src/magnumCompatibility.h   | 25 +++++++++++++++++++++++++
 src/magnumConfigure.h.cmake |  1 +
 6 files changed, 34 insertions(+)
 create mode 100644 src/magnumCompatibility.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 014b64876..83e06fefc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,7 @@ cmake_minimum_required(VERSION 2.8.8)
 project(Magnum)
 
 option(TARGET_GLES "Build for OpenGL ES 2 instead of desktop OpenGL" OFF)
+option(GCC45_COMPATIBILITY "Enable compatibility mode for GCC 4.5 (might disable some features)" OFF)
 
 option(BUILD_TESTS "Build unit tests (requires Qt4)." OFF)
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index c88df8331..287697878 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -4,6 +4,10 @@ if(TARGET_GLES)
     set(MAGNUM_TARGET_GLES 1)
 endif()
 
+if(GCC45_COMPATIBILITY)
+    set(MAGNUM_GCC45_COMPATIBILITY 1)
+endif()
+
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/magnumConfigure.h.cmake
                ${CMAKE_CURRENT_BINARY_DIR}/magnumConfigure.h)
 
diff --git a/src/Math/Math.h b/src/Math/Math.h
index e6e7e24b5..3a2ebf049 100644
--- a/src/Math/Math.h
+++ b/src/Math/Math.h
@@ -17,6 +17,7 @@
 
 #include <cstddef>
 
+#include "magnumCompatibility.h"
 #include "magnumVisibility.h"
 
 /** @file
diff --git a/src/Math/MathTypeTraits.h b/src/Math/MathTypeTraits.h
index c1a989f8a..c41634ce5 100644
--- a/src/Math/MathTypeTraits.h
+++ b/src/Math/MathTypeTraits.h
@@ -21,6 +21,8 @@
 
 #include <cmath>
 
+#include "magnumCompatibility.h"
+
 /** @brief Precision when testing floats for equality */
 #ifndef FLOAT_EQUALITY_PRECISION
 #define FLOAT_EQUALITY_PRECISION 1.0e-6
diff --git a/src/magnumCompatibility.h b/src/magnumCompatibility.h
new file mode 100644
index 000000000..311430e9e
--- /dev/null
+++ b/src/magnumCompatibility.h
@@ -0,0 +1,25 @@
+#ifndef magnumCompatibility_h
+#define magnumCompatibility_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "magnumConfigure.h"
+
+#ifdef MAGNUM_GCC45_COMPATIBILITY
+#define constexpr
+#define nullptr 0
+#endif
+
+#endif
diff --git a/src/magnumConfigure.h.cmake b/src/magnumConfigure.h.cmake
index 9e8a3c7e8..7204ad4b7 100644
--- a/src/magnumConfigure.h.cmake
+++ b/src/magnumConfigure.h.cmake
@@ -1 +1,2 @@
 #cmakedefine MAGNUM_TARGET_GLES
+#cmakedefine MAGNUM_GCC45_COMPATIBILITY