Merge branch 'master' of https://github.com/Z3Prover/z3 into jan4

src/util/ref_vector.h

@@ -89,9 +89,10 @@ public:
         m_nodes.shrink(sz);
     }
 
-    void push_back(T * n) {
+    ref_vector_core& push_back(T * n) {
         inc_ref(n);
         m_nodes.push_back(n);
+        return *this;
     }
 
     void pop_back() {

src/util/scoped_ptr_vector.h

@@ -30,6 +30,7 @@ public:
     ~scoped_ptr_vector() { reset(); }
     void reset() { std::for_each(m_vector.begin(), m_vector.end(), delete_proc<T>()); m_vector.reset(); }
     void push_back(T * ptr) { m_vector.push_back(ptr); }
+    void pop_back() { SASSERT(!empty()); set(size()-1, 0); m_vector.pop_back(); }
     T * operator[](unsigned idx) const { return m_vector[idx]; }
     void set(unsigned idx, T * ptr) { 
         if (m_vector[idx] == ptr) 

src/util/scoped_vector.h

@@ -46,7 +46,7 @@ public:
         m_elems_lim.push_back(m_elems_start);
     }
 
-    void pop_scopes(unsigned num_scopes) {
+    void pop_scope(unsigned num_scopes) {
         if (num_scopes == 0) return;
         unsigned new_size = m_sizes.size() - num_scopes;
         unsigned src_lim = m_src_lim[new_size];
@@ -72,6 +72,12 @@ public:
         return m_elems[m_index[idx]];
     }
 
+    // breaks abstraction, caller must ensure backtracking.
+    T& ref(unsigned idx) {
+        SASSERT(idx < m_size);
+        return m_elems[m_index[idx]];
+    }
+
     void set(unsigned idx, T const& t) {
         SASSERT(idx < m_size);
         unsigned n = m_index[idx];
@@ -102,6 +108,13 @@ public:
         SASSERT(invariant());
     }
 
+    void erase_and_swap(unsigned i) {
+        if (i + 1 < size()) {
+            set(i, m_elems[m_index[size()-1]]);
+        }
+        pop_back();
+    }
+
     unsigned size() const { return m_size; }
     
     bool empty() const { return m_size == 0; }