Guarantee inlining of some important functions

src/graph/fast_vector_property_map.hh

@@ -164,7 +164,7 @@ public:
 
     void reserve(size_t size) const { _checked.reserve(size); }
 
-    reference operator[](const key_type& v) const
+    reference operator[](const key_type& v) const __attribute__((always_inline))
     {
         typename property_traits<IndexMap>::value_type i =
             get(_checked.index, v);

src/graph/graph_filtering.hh

@@ -147,7 +147,7 @@ public:
         : _filtered_property(filtered_property), _invert(invert) {}
 
     template <class Descriptor>
-    inline bool operator() (Descriptor d) const
+    __attribute__((always_inline)) inline bool operator() (Descriptor d) const
     {
         // ignore if masked