add static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size())

Adds a NUM_SUBRELATIONS sentinel to each SubrelationIndex enum and a
static_assert to catch enum/array size mismatches at compile time.

Author: notnotraju

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_bools_relation.hpp

@@ -49,11 +49,13 @@ template <typename FF_> class ECCVMBoolsRelationImpl {
         BOOL_MSM_ADD2 = 20,
         BOOL_MSM_ADD3 = 21,
         BOOL_MSM_ADD4 = 22,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 23> SUBRELATION_PARTIAL_LENGTHS{
         3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
     };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     template <typename ContainerOverSubrelations, typename AllEntities, typename Parameters>
     static void accumulate(ContainerOverSubrelations& accumulator,

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_lookup_relation.hpp

@@ -26,12 +26,14 @@ template <typename FF_> class ECCVMLookupRelationImpl {
     enum SubrelationIndex : size_t {
         GRAND_PRODUCT = 0,
         LEFT_SHIFTABLE = 1,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 2> SUBRELATION_PARTIAL_LENGTHS{
         LENGTH, // grand product construction sub-relation
         LENGTH  // left-shiftable polynomial sub-relation
     };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     static constexpr std::array<bool, 2> SUBRELATION_LINEARLY_INDEPENDENT = { true, false };
 

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_msm_relation.hpp

@@ -122,11 +122,13 @@ template <typename FF_> class ECCVMMSMRelationImpl {
         // No-op row: accumulator preservation when no selector is active
         NO_OP_ACC_X = 45,
         NO_OP_ACC_Y = 46,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 47> SUBRELATION_PARTIAL_LENGTHS{ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
                                                                          8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
                                                                          8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     template <typename ContainerOverSubrelations, typename AllEntities, typename Parameters>
     static void accumulate(ContainerOverSubrelations& accumulator,

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_point_table_relation.hpp

@@ -36,9 +36,11 @@ template <typename FF_> class ECCVMPointTableRelationImpl {
         // Point addition: T = T_shift + D when not at transition
         ADD_X = 4,
         ADD_Y = 5,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 6> SUBRELATION_PARTIAL_LENGTHS{ 6, 6, 6, 6, 6, 6 };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     template <typename ContainerOverSubrelations, typename AllEntities, typename Parameters>
     static void accumulate(ContainerOverSubrelations& accumulator,

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_set_relation.hpp

@@ -30,12 +30,14 @@ template <typename FF_> class ECCVMSetRelationImpl {
     enum SubrelationIndex : size_t {
         GRAND_PRODUCT = 0,
         LEFT_SHIFTABLE = 1,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 2> SUBRELATION_PARTIAL_LENGTHS{
         22, // grand product construction sub-relation
         3   // left-shiftable polynomial sub-relation
     };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
     // prover optimization to allow for skipping the computation of sub-relations at certain points in sumcheck.
     template <typename AllEntities> inline static bool skip(const AllEntities& in)
     {

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_transcript_relation.hpp

@@ -99,11 +99,13 @@ template <typename FF_> class ECCVMTranscriptRelationImpl {
         INFINITY_ACC_X = 29,
         // Infinity flag consistency: acc_y = 0 when accumulator empty
         INFINITY_ACC_Y = 30,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 31> SUBRELATION_PARTIAL_LENGTHS{
         8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
     };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     template <typename ContainerOverSubrelations, typename AllEntities, typename Parameters>
     static void accumulate(ContainerOverSubrelations& accumulator,

barretenberg/cpp/src/barretenberg/relations/ecc_vm/ecc_wnaf_relation.hpp

@@ -85,10 +85,12 @@ template <typename FF_> class ECCVMWnafRelationImpl {
         INACTIVE_POINT_TRANSITION = 21,
         // Precompute select shape: monotonically non-decreasing after first row
         PRECOMPUTE_SELECT_SHAPE = 22,
+        NUM_SUBRELATIONS,
     };
 
     static constexpr std::array<size_t, 23> SUBRELATION_PARTIAL_LENGTHS{ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
                                                                          5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 };
+    static_assert(NUM_SUBRELATIONS == SUBRELATION_PARTIAL_LENGTHS.size());
 
     template <typename ContainerOverSubrelations, typename AllEntities, typename Parameters>
     static void accumulate(ContainerOverSubrelations& accumulator,