[0.6] [MOD-11651] Fix wrong template type deduction in GenerateAndAddVector (#789)

* [MOD-11651] Fix wrong template type deduction in `GenerateAndAddVector` (#785)

Prevent template deduction errors in GenerateAndAddVector by making data_t parameter non-deducible

Used std::type_identity<data_t>::type for the value parameter to force explicit template specification (e.g., GenerateAndAddVector<double>()) instead of allowing compiler to incorrectly deduce int from literal values, which caused buffer overflows when index expected different data types.

(cherry picked from commit 961d6eb)

* Upgrade unit tests C++ standard to C++20

Author: meiravgri

tests/benchmark/CMakeLists.txt

@@ -4,7 +4,7 @@ message("# VectorSimilarity_Benchmark binroot: " ${binroot})
 
 project(VectorSimilarity_Benchmark)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 20)
 
 set(CMAKE_CXX_FLAGS_DEBUG "-g")
 set(CMAKE_CXX_FLAGS_RELEASE "-O3")

tests/unit/CMakeLists.txt

@@ -11,7 +11,7 @@ project(VectorSimilarity_UnitTest)
 
 include(CTest)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 20)
 
 set(CMAKE_CXX_FLAGS_DEBUG "-g")
 set(CMAKE_CXX_FLAGS_RELEASE "-O3")

tests/unit/test_bruteforce_multi.cpp

@@ -1280,7 +1280,7 @@ TYPED_TEST(BruteForceMultiTest, rangeQuery) {
         GenerateAndAddVector<TEST_DATA_T>(index, dim, i, i);
         // Add some vectors, worst than the second loop (for the given query)
         for (size_t j = 0; j < per_label - 1; j++)
-            GenerateAndAddVector(index, dim, i, (TEST_DATA_T)i + n);
+            GenerateAndAddVector<TEST_DATA_T>(index, dim, i, (TEST_DATA_T)i + n);
     }
 
     ASSERT_EQ(VecSimIndex_IndexSize(index), n);

tests/unit/test_utils.h

@@ -34,8 +34,10 @@ static void GenerateVector(data_t *output, size_t dim, data_t value = 1.0) {
     }
 }
 
+// use std::type_identity to force explicit template specification.
 template <typename data_t>
-int GenerateAndAddVector(VecSimIndex *index, size_t dim, size_t id, data_t value = 1.0) {
+int GenerateAndAddVector(VecSimIndex *index, size_t dim, size_t id,
+                         typename std::type_identity<data_t>::type value = 1.0) {
     data_t v[dim];
     GenerateVector(v, dim, value);
     return VecSimIndex_AddVector(index, v, id);