compile error with g++-4.7

[aimxhaisse]

It seems that there is a missing include with g++-4.7:

$ make CXX=g++-4.7
g++-4.7 -g -Wall -Werror -I. -I./include -std=gnu++11  -DROCKSDB_PLATFORM_POSIX  -DOS_LINUX -fno-builtin-memcmp -DROCKSDB_FALLOCATE_PRESENT -DGFLAGS -DZLIB -DBZIP2   -DHAVE_JEMALLOC -O2 -fno-omit-frame-pointer -momit-leaf-frame-pointer -Woverloaded-virtual -c db/compaction.cc -o db/compaction.o 
In file included from ./db/compaction.h:11:0,
                 from db/compaction.cc:10:
./db/version_set.h:437:3: error: 'atomic' in namespace 'std' does not name a type
./db/version_set.h: In member function 'uint64_t rocksdb::VersionSet::LastSequence() const':
./db/version_set.h:333:12: error: 'last_sequence_' was not declared in this scope
./db/version_set.h:333:32: error: 'memory_order_acquire' is not a member of 'std'
./db/version_set.h: In member function 'void rocksdb::VersionSet::SetLastSequence(uint64_t)':
./db/version_set.h:338:5: error: 'last_sequence_' was not declared in this scope
./db/version_set.h:339:29: error: 'memory_order_release' is not a member of 'std'
make: *** [db/compaction.o] Error 1

[aimxhaisse]

Fixed with the following patch:

diff --git a/db/version_set.h b/db/version_set.h
index 376b259..da23772 100644
--- a/db/version_set.h
+++ b/db/version_set.h
@@ -18,6 +18,7 @@
 // synchronization on all accesses.

 #pragma once
+#include <atomic>
 #include <map>
 #include <memory>
 #include <set>

[igorcanadi]

Tnx for the report! Fixed with e57f0cc