core: make SizeCounter use pointer instead of reference
Restore virtual inheritance of GenericLinkServiceCounters in
GenericLinkService
refs #3941
Change-Id: I368e4694fee7bc97173fddfc81d0c679da0d6eed
diff --git a/core/counter.hpp b/core/counter.hpp
index bb50c66..3a678ec 100644
--- a/core/counter.hpp
+++ b/core/counter.hpp
@@ -1,6 +1,6 @@
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
- * Copyright (c) 2014-2015, Regents of the University of California,
+ * Copyright (c) 2014-2017, Regents of the University of California,
* Arizona Board of Regents,
* Colorado State University,
* University Pierre & Marie Curie, Sorbonne University,
@@ -107,15 +107,17 @@
/** \brief provides a counter that observes the size of a table
* \tparam T a type that provides a size() const member function
+ *
+ * if table not specified in constructor, it can be added later by invoking observe()
*/
template<typename T>
class SizeCounter
{
public:
- typedef size_t rep;
+ typedef size_t Rep;
- constexpr
- SizeCounter(const T& table)
+ explicit constexpr
+ SizeCounter(const T* table = nullptr)
: m_table(table)
{
}
@@ -125,15 +127,22 @@
SizeCounter&
operator=(const SizeCounter&) = delete;
+ void
+ observe(const T* table)
+ {
+ m_table = table;
+ }
+
/** \brief observe the counter
*/
- operator rep() const
+ operator Rep() const
{
- return m_table.size();
+ BOOST_ASSERT(m_table != nullptr);
+ return m_table->size();
}
private:
- const T& m_table;
+ const T* m_table;
};
} // namespace nfd