The type being updated is not necessarily the same as the type of the Duoram

Because we'll shortly be allowing for individual fields of wide storage
values to be updated

duoram.hpp

@@ -338,9 +338,13 @@ class Duoram<T>::Shape::MemRefS : public Duoram<T>::Shape::MemRef {
 
 private:
     // Oblivious update to a shared index of Duoram memory, only for
-    // T = RegAS or RegXS
-    MemRefS<U> &oram_update(const T& M, const prac_template_true&);
-    MemRefS<U> &oram_update(const T& M, const prac_template_false&);
+    // ST = RegAS or RegXS
+    template <typename ST>
+    MemRefS<U> &oram_update(const ST& M, const prac_template_true&);
+    // Oblivious update to a shared index of Duoram memory, for
+    // ST not RegAS or RegXS
+    template <typename ST>
+    MemRefS<U> &oram_update(const ST& M, const prac_template_false&);
 
 public:
     MemRefS<U>(Shape &shape, const U &idx) :

duoram.tcc

@@ -357,10 +357,10 @@ Duoram<T>::Shape::MemRefS<U>::operator T()
 }
 
 // Oblivious update to a shared index of Duoram memory, only for
-// T = RegAS or RegXS
-template <typename T> template <typename U>
+// ST = RegAS or RegXS
+template <typename T> template <typename U> template <typename ST>
 typename Duoram<T>::Shape::template MemRefS<U>
-    &Duoram<T>::Shape::MemRefS<U>::oram_update(const T& M,
+    &Duoram<T>::Shape::MemRefS<U>::oram_update(const ST& M,
         const prac_template_true &)
 {
     Shape &shape = this->shape;
@@ -375,7 +375,7 @@ typename Duoram<T>::Shape::template MemRefS<U>
         U indoffset = dt.target<U>();
         indoffset -= idx;
         auto Moffset = std::make_tuple(M, M, M);
-        Moffset -= dt.scaled_value<T>();
+        Moffset -= dt.scaled_value<ST>();
 
         // Send them to the peer, and everything except the first offset
         // to the server
@@ -389,7 +389,7 @@ typename Duoram<T>::Shape::template MemRefS<U>
 
         // Receive the above from the peer
         U peerindoffset;
-        std::tuple<T,T,T> peerMoffset;
+        std::tuple<ST,ST,ST> peerMoffset;
         shape.tio.recv_peer(&peerindoffset, BITBYTES(shape.addr_size));
         shape.tio.iostream_peer() >> peerMoffset;
 
@@ -405,7 +405,7 @@ typename Duoram<T>::Shape::template MemRefS<U>
         pe.reduce(init, [&dt, &shape, &Mshift, player] (int thread_num,
                 address_t i, const RDPFTriple::node &leaf) {
             // The values from the three DPFs
-            auto [V0, V1, V2] = dt.scaled<T>(leaf) + dt.unit<T>(leaf) * Mshift;
+            auto [V0, V1, V2] = dt.scaled<ST>(leaf) + dt.unit<ST>(leaf) * Mshift;
             // References to the appropriate cells in our database, our
             // blind, and our copy of the peer's blinded database
             auto [DB, BL, PBD] = shape.get_comp(i);
@@ -424,7 +424,7 @@ typename Duoram<T>::Shape::template MemRefS<U>
 
         RDPFPair dp = shape.tio.rdpfpair(shape.yield, shape.addr_size);
         U p0indoffset, p1indoffset;
-        std::tuple<T,T> p0Moffset, p1Moffset;
+        std::tuple<ST,ST> p0Moffset, p1Moffset;
 
         shape.yield();
 
@@ -445,7 +445,7 @@ typename Duoram<T>::Shape::template MemRefS<U>
         pe.reduce(init, [&dp, &shape, &Mshift] (int thread_num,
                 address_t i, const RDPFPair::node &leaf) {
             // The values from the two DPFs
-            auto V = dp.scaled<T>(leaf) + dp.unit<T>(leaf) * Mshift;
+            auto V = dp.scaled<ST>(leaf) + dp.unit<ST>(leaf) * Mshift;
             // shape.get_server(i) returns a pair of references to the
             // appropriate cells in the two blinded databases, so we can
             // subtract the pair directly.
@@ -457,10 +457,10 @@ typename Duoram<T>::Shape::template MemRefS<U>
 }
 
 // Oblivious update to a shared index of Duoram memory, only for
-// T not equal to RegAS or RegXS
-template <typename T> template <typename U>
+// ST not RegAS or RegXS
+template <typename T> template <typename U> template <typename ST>
 typename Duoram<T>::Shape::template MemRefS<U>
-    &Duoram<T>::Shape::MemRefS<U>::oram_update(const T& M,
+    &Duoram<T>::Shape::MemRefS<U>::oram_update(const ST& M,
         const prac_template_false &)
 {
     return *this;