aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMax Kellermann <max@duempel.org>2014-07-14 16:24:07 +0200
committerMax Kellermann <max@duempel.org>2014-07-14 16:24:07 +0200
commit7a1f3177c92556c4ca224d28fc881686845c5052 (patch)
tree158b962f07f6877ad33ebd6e590475fb6c0d6833
parentf8da8b02615bc5b8a358407da147c97debc40e06 (diff)
downloadmpd-7a1f3177c92556c4ca224d28fc881686845c5052.tar.gz
mpd-7a1f3177c92556c4ca224d28fc881686845c5052.tar.xz
mpd-7a1f3177c92556c4ca224d28fc881686845c5052.zip
util/Cast: reimplement as template without macro
-rw-r--r--src/output/plugins/httpd/HttpdInternal.hxx14
-rw-r--r--src/tag/TagPool.cxx7
-rw-r--r--src/util/Cast.hxx28
3 files changed, 33 insertions, 16 deletions
diff --git a/src/output/plugins/httpd/HttpdInternal.hxx b/src/output/plugins/httpd/HttpdInternal.hxx
index a16c60bc3..5c113520d 100644
--- a/src/output/plugins/httpd/HttpdInternal.hxx
+++ b/src/output/plugins/httpd/HttpdInternal.hxx
@@ -152,19 +152,13 @@ public:
HttpdOutput(EventLoop &_loop);
~HttpdOutput();
-#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#if defined(__clang__) || GCC_CHECK_VERSION(4,7)
+ constexpr
#endif
-
- static constexpr HttpdOutput *Cast(AudioOutput *ao) {
- return ContainerCast(ao, HttpdOutput, base);
+ static HttpdOutput *Cast(AudioOutput *ao) {
+ return &ContainerCast(*ao, &HttpdOutput::base);
}
-#if GCC_CHECK_VERSION(4,6) || defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
using DeferredMonitor::GetEventLoop;
bool Init(const config_param &param, Error &error);
diff --git a/src/tag/TagPool.cxx b/src/tag/TagPool.cxx
index 0b6bc956c..29f605337 100644
--- a/src/tag/TagPool.cxx
+++ b/src/tag/TagPool.cxx
@@ -87,10 +87,13 @@ calc_hash(TagType type, const char *p)
return hash ^ type;
}
-static inline constexpr TagPoolSlot *
+#if defined(__clang__) || GCC_CHECK_VERSION(4,7)
+ constexpr
+#endif
+static inline TagPoolSlot *
tag_item_to_slot(TagItem *item)
{
- return ContainerCast(item, TagPoolSlot, item);
+ return &ContainerCast(*item, &TagPoolSlot::item);
}
static inline TagPoolSlot **
diff --git a/src/util/Cast.hxx b/src/util/Cast.hxx
index 8eb3479b8..680f81704 100644
--- a/src/util/Cast.hxx
+++ b/src/util/Cast.hxx
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2013 Max Kellermann <max@duempel.org>
+ * Copyright (C) 2013-2014 Max Kellermann <max@duempel.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -64,11 +64,31 @@ OffsetCast(const U *p, ptrdiff_t offset)
return reinterpret_cast<const T *>(OffsetPointer(p, offset));
}
+template<class C, class A>
+static constexpr inline ptrdiff_t
+ContainerAttributeOffset(const C *null_c, const A C::*p)
+{
+ return ptrdiff_t((const char *)null_c - (const char *)&(null_c->*p));
+}
+
+template<class C, class A>
+static constexpr inline ptrdiff_t
+ContainerAttributeOffset(const A C::*p)
+{
+ return ContainerAttributeOffset<C, A>(nullptr, p);
+}
+
/**
* Cast the given pointer to a struct member to its parent structure.
*/
-#define ContainerCast(p, container, attribute) \
- OffsetCast<container, decltype(((container*)nullptr)->attribute)> \
- ((p), -ptrdiff_t(offsetof(container, attribute)))
+template<class C, class A>
+#if defined(__clang__) || GCC_CHECK_VERSION(4,7)
+constexpr
+#endif
+static inline C &
+ContainerCast(A &a, A C::*member)
+{
+ return *OffsetCast<C, A>(&a, ContainerAttributeOffset<C, A>(member));
+}
#endif