fix a 'multiple definition' error when included by multiple sources:
src/common/versioned_variant.h:31: multiple definition of `ceph::encode(std::monostate const&, ceph::buffer::v15_2_0::list&)';
rgw_main.cc.o:src/common/versioned_variant.h:31: first defined here
Signed-off-by: Casey Bodley <cbodley@redhat.com>
namespace ceph {
// null encoding for std::monostate
-void encode(const std::monostate&, bufferlist& bl) {}
-void decode(std::monostate&, bufferlist::const_iterator& p) {}
+inline void encode(const std::monostate&, bufferlist& bl) {}
+inline void decode(std::monostate&, bufferlist::const_iterator& p) {}
// largest value that can be represented by `__u8 struct_v`
inline constexpr size_t max_version = std::numeric_limits<__u8>::max();