Fix QuantizedGraph<float> source compatibility for v0.3.6

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.15)
 
-project(RaBitQLib VERSION 0.3.5 LANGUAGES CXX)
+project(RaBitQLib VERSION 0.3.6 LANGUAGES CXX)
 
 include(CMakePackageConfigHelpers)
 include(GNUInstallDirs)

docs/docs/index/qg.md

@@ -40,18 +40,19 @@ window; `ef` controls the query search window. Python defaults to one thread.
 ### C++
 
 The C++ API uses the float-only `rabitqlib::symqg::QuantizedGraph` and `QGBuilder`.
-`QuantizedGraph` is a non-template class; use `QuantizedGraph` instead of
-`QuantizedGraph<float>`. Its implementation is compiled in `src/index/qg.cpp`:
+`QuantizedGraph<float>` retains the C++ template API, with its implementation
+compiled in `src/index/qg.cpp`. C++17 variable declarations can also omit `<float>`
+through class template argument deduction:
 
 ```cpp
-QuantizedGraph(
+QuantizedGraph<float>(
     size_t num, size_t dim, size_t max_deg,
     MetricType metric_type = METRIC_L2,
     RotatorType rotator_type = RotatorType::FhtKacRotator,
     size_t quantization_bits = 0
 );
 QGBuilder(
-    QuantizedGraph& index, uint32_t ef_build, const float* data,
+    QuantizedGraph<float>& index, uint32_t ef_build, const float* data,
     size_t num_threads = std::numeric_limits<size_t>::max(),
     QGInitialization init = QGInitialization::PiPNN
 );
@@ -66,7 +67,7 @@ The builder handles initialization internally.
 using namespace rabitqlib::symqg;
 
 // data contains rows * cols floats.
-QuantizedGraph qg(rows, cols, 32);
+QuantizedGraph<float> qg(rows, cols, 32);
 {
     QGBuilder builder(qg, 200, data.data(), 32, QGInitialization::PiPNN);
     builder.build();
@@ -99,7 +100,7 @@ C++ search accepts one vector in the original input dimension and writes `k` IDs
 and distances:
 
 ```cpp
-QuantizedGraph qg;
+QuantizedGraph<float> qg;
 qg.load("qg_example.index");
 qg.set_ef(100);
 

include/rabitqlib/index/symqg/qg.hpp

@@ -35,7 +35,11 @@ class QuantizedQuery {
     [[nodiscard]] float g_add() const;
 };
 
-class QuantizedGraph {
+template <typename T = float>
+class QuantizedGraph;
+
+template <>
+class QuantizedGraph<float> {
     friend class QGBuilder;
     friend struct QGConstructionTestAccess;
 
@@ -187,4 +191,16 @@ class QuantizedGraph {
     );
 };
 
+// Preserve C++17 deduction for callers that omit the float template argument.
+QuantizedGraph()->QuantizedGraph<float>;
+QuantizedGraph(
+    size_t,
+    size_t,
+    size_t,
+    MetricType = METRIC_L2,
+    RotatorType = RotatorType::FhtKacRotator,
+    size_t = 0
+)
+    ->QuantizedGraph<float>;
+
 }  // namespace rabitqlib::symqg

include/rabitqlib/index/symqg/qg_builder.hpp

@@ -32,7 +32,7 @@ class QGBuilder {
     friend struct QGConstructionTestAccess;
 
    private:
-    QuantizedGraph& qg_;
+    QuantizedGraph<float>& qg_;
     size_t ef_build_;      // size of search pool for indexing
     size_t num_threads_;   // number of threads used for indexing
     size_t num_nodes_;     // num of data points
@@ -59,7 +59,7 @@ class QGBuilder {
 
     void initialize_storage(const float* data);
 
-    QGBuilder(QuantizedGraph& index, uint32_t ef_build, size_t num_threads)
+    QGBuilder(QuantizedGraph<float>& index, uint32_t ef_build, size_t num_threads)
         : qg_{index}
         , ef_build_{ef_build}
         , num_threads_{std::max<size_t>(1, std::min(num_threads, total_threads()))}
@@ -69,7 +69,7 @@ class QGBuilder {
 
    public:
     explicit QGBuilder(
-        QuantizedGraph& index,
+        QuantizedGraph<float>& index,
         uint32_t ef_build,
         const float* data,
         size_t num_threads = std::numeric_limits<size_t>::max(),

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "scikit_build_core.build"
 
 [project]
 name = "rabitqlib"
-version = "0.3.5"
+version = "0.3.6"
 description = "RaBitQ Python bindings for HNSW, IVF, and SymQG"
 readme = "README.md"
 requires-python = ">=3.11"

python_bindings/symqg_bindings.cpp

@@ -66,7 +66,7 @@ class SymqgIndex {
         }
 
         num_points_ = static_cast<size_t>(data_array.shape(0));
-        index_ = std::make_unique<rabitqlib::symqg::QuantizedGraph>(
+        index_ = std::make_unique<rabitqlib::symqg::QuantizedGraph<float>>(
             num_points_,
             dim_,
             max_degree_,
@@ -167,7 +167,7 @@ class SymqgIndex {
 
     static SymqgIndex load(const std::string& path) {
         SymqgIndex wrapper;
-        wrapper.index_ = std::make_unique<rabitqlib::symqg::QuantizedGraph>();
+        wrapper.index_ = std::make_unique<rabitqlib::symqg::QuantizedGraph<float>>();
         wrapper.index_->load(path.c_str());
         wrapper.num_points_ = wrapper.index_->num_vertices();
         wrapper.dim_ = wrapper.index_->dimension();
@@ -194,7 +194,7 @@ class SymqgIndex {
     rabitqlib::MetricType metric_ = rabitqlib::METRIC_L2;
     size_t quantization_bits_ = 0;
     bool built_ = false;
-    std::unique_ptr<rabitqlib::symqg::QuantizedGraph> index_;
+    std::unique_ptr<rabitqlib::symqg::QuantizedGraph<float>> index_;
 };
 
 }  // namespace rabitqlib::python_bindings

sample/cpp/symqg_indexing.cpp

@@ -12,7 +12,7 @@
 #include "rabitqlib/utils/stopw.hpp"
 
 using PID = rabitqlib::PID;
-using index_type = rabitqlib::symqg::QuantizedGraph;
+using index_type = rabitqlib::symqg::QuantizedGraph<float>;
 using data_type = rabitqlib::RowMajorArray<float>;
 using gt_type = rabitqlib::RowMajorArray<uint32_t>;
 

sample/cpp/symqg_querying.cpp

@@ -7,7 +7,7 @@
 #include "rabitqlib/utils/stopw.hpp"
 
 using PID = rabitqlib::PID;
-using index_type = rabitqlib::symqg::QuantizedGraph;
+using index_type = rabitqlib::symqg::QuantizedGraph<float>;
 using data_type = rabitqlib::RowMajorArray<float>;
 using gt_type = rabitqlib::RowMajorArray<uint32_t>;