Fix build (#454)

* Fix C++11 syntax. It fixes build with GCC.

* Be Python 3.x compatible by replacing print "XXX" by print("XXX")
diff --git a/SConstruct b/SConstruct
index 532001a..8307d47 100644
--- a/SConstruct
+++ b/SConstruct
@@ -72,12 +72,12 @@
     Return()
 
 if env['neon'] and 'x86' in env['arch']:
-    print "Cannot compile NEON for x86"
+    print("Cannot compile NEON for x86")
     Exit(1)
 
 if env['set_soname'] and not version_at_least(SCons.__version__, "2.4"):
-    print "Setting the library's SONAME / SHLIBVERSION requires SCons 2.4 or above"
-    print "Update your version of SCons or use set_soname=0"
+    print("Setting the library's SONAME / SHLIBVERSION requires SCons 2.4 or above")
+    print("Update your version of SCons or use set_soname=0")
     Exit(1)
 
 if env['os'] == 'bare_metal':
@@ -99,7 +99,7 @@
 c_compiler = os.environ.get('CC', default_c_compiler)
 
 if env['os'] == 'android' and ( 'clang++' not in cpp_compiler or 'clang' not in c_compiler ):
-    print "WARNING: Only clang is officially supported to build the Compute Library for Android"
+    print( "WARNING: Only clang is officially supported to build the Compute Library for Android")
 
 if 'clang++' in cpp_compiler:
     env.Append(CXXFLAGS = ['-Wno-format-nonliteral','-Wno-deprecated-increment-bool','-Wno-vla-extension','-Wno-mismatched-tags'])
@@ -111,7 +111,7 @@
 
 if env['openmp']:
     if 'clang++' in cpp_compiler:
-        print "Clang does not support OpenMP. Use scheduler=cpp."
+        print( "Clang does not support OpenMP. Use scheduler=cpp.")
         Exit(1)
 
     env.Append(CPPDEFINES = [('ARM_COMPUTE_OPENMP_SCHEDULER', 1)])
@@ -179,10 +179,10 @@
 
     if 'clang++' not in cpp_compiler:
         if env['arch'] == 'arm64-v8.2-a' and not version_at_least(compiler_ver, '6.2.1'):
-            print "GCC 6.2.1 or newer is required to compile armv8.2-a code"
+            print("GCC 6.2.1 or newer is required to compile armv8.2-a code")
             Exit(1)
         elif env['arch'] == 'arm64-v8a' and not version_at_least(compiler_ver, '4.9'):
-            print "GCC 4.9 or newer is required to compile NEON code for AArch64"
+            print("GCC 4.9 or newer is required to compile NEON code for AArch64")
             Exit(1)
 
         if version_at_least(compiler_ver, '6.1'):
diff --git a/include/half/half.hpp b/include/half/half.hpp
index 0d7459b..81976bc 100644
--- a/include/half/half.hpp
+++ b/include/half/half.hpp
@@ -272,7 +272,7 @@
 	/// ~~~~

 	namespace literal

 	{

-		half operator""_h(long double);

+		half operator"" _h(long double);

 	}

 #endif

 

@@ -1083,7 +1083,7 @@
 		friend struct std::hash<half>;

 	#endif

 	#if HALF_ENABLE_CPP11_USER_LITERALS

-		friend half literal::operator""_h(long double);

+		friend half literal::operator"" _h(long double);

 	#endif

 

 	public:

@@ -1196,7 +1196,7 @@
 		/// to rather involved conversions.

 		/// \param value literal value

 		/// \return half with given value (if representable)

-		inline half operator""_h(long double value) { return half(detail::binary, detail::float2half<half::round_style>(value)); }

+		inline half operator"" _h(long double value) { return half(detail::binary, detail::float2half<half::round_style>(value)); }

 	}

 #endif