MSVC's throw() behaviour matches the C++11 noexcept, so use it

This allows code using methods marked Q_DECL_NOEXCEPT to benefit from
optimisations before MSVC supports the C++11 keyword. Even MSVC 2012
doesn't have it yet.

Using throw() in other compilers is not a good idea because they might
actually be implementing the C++ standard -- which is broken.

Change-Id: Id07ab4fe40a641583d5285d5abb536998bc419ba
Reviewed-by: Marius Storm-Olsen <marius.storm-olsen@nokia.com>

diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 6cc754c..9a9e78b 100644 (file)
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -110,6 +110,10 @@
 #    define Q_COMPILER_VARIADIC_MACROS
 #  endif
 
+// make sure that these aren't defined when Q_COMPILER_NOEXCEPT is defined
+#  define Q_DECL_NOEXCEPT  throw()
+#  define Q_DECL_NOEXCEPT_EXPR(x)
+
 #if defined(Q_CC_MSVC) && _MSC_VER >= 1600
 #      define Q_COMPILER_RVALUE_REFS
 #      define Q_COMPILER_AUTO_TYPE
@@ -724,7 +728,7 @@
 #ifdef Q_COMPILER_NOEXCEPT
 # define Q_DECL_NOEXCEPT noexcept
 # define Q_DECL_NOEXCEPT_EXPR(x) noexcept(x)
-#else
+#elif !defined(Q_DECL_NOEXCEPT)
 # define Q_DECL_NOEXCEPT
 # define Q_DECL_NOEXCEPT_EXPR(x)
 #endif