Using fp_const for hypergrid granularity

sample/simple/main.cpp

@@ -344,7 +344,7 @@ void pesa() {
       .stop(criteria::generation_limit{100})
       .rank<pareto_preserved_t>(gal::rank::binary{})
       .elite(elite::strict{})
-      .cluster(cluster::hypergrid<std::array<double, 2>, 0.1, 0.1>{})
+      .cluster(cluster::hypergrid<std::array<double, 2>, 0.1_dc, 0.1_dc>{})
       .crowd(crowd::cluster{})
       .prune(prune::cluster_random{rng})
       .project(project::factory<project::truncate, crowd_density_t>{})
@@ -380,7 +380,7 @@ void pesa_ii() {
       .stop(criteria::generation_limit{100})
       .rank<pareto_preserved_t>(gal::rank::binary{})
       .elite(elite::strict{})
-      .cluster(cluster::hypergrid<std::array<double, 2>, 0.1, 0.1>{})
+      .cluster(cluster::hypergrid<std::array<double, 2>, 0.1_dc, 0.1_dc>{})
       .crowd(crowd::none{})
       .prune(prune::cluster_random{rng})
       .project(project::factory<project::none>{})

src/inc/clustering.hpp

@@ -313,10 +313,15 @@ namespace details {
     return result;
   }
 
+  template<typename Fitness>
+  using hypergrid_granularity_t =
+      literals::to_const_type<multiobjective_value_t<Fitness>>;
+
 } // namespace details
 
 // hypercell (pesa, pesa-ii, paes)
-template<grid_fitness Fitness, multiobjective_value_t<Fitness>... Granularity>
+template<grid_fitness Fitness,
+         details::hypergrid_granularity_t<Fitness>... Granularity>
 class hypergrid {
 private:
   inline static constexpr std::array<multiobjective_value_t<Fitness>,

src/inc/literals.hpp

@@ -56,17 +56,35 @@ inline constexpr fp_const<float> operator""_fc(long double value) noexcept {
   return fp_const{static_cast<float>(value)};
 }
 
-template<typename Ty>
-struct underlying_const_type_impl {
-  using type = Ty;
-};
+namespace details {
+
+  template<typename Ty>
+  struct underlying_const_type_impl {
+    using type = Ty;
+  };
+
+  template<typename Ty>
+  struct underlying_const_type_impl<fp_const<Ty>> {
+    using type = typename fp_const<Ty>::value_t;
+  };
+
+  template<typename Ty>
+  struct to_const_type_impl {
+    using type = Ty;
+  };
+
+  template<std::floating_point Ty>
+  struct to_const_type_impl<Ty> {
+    using type = fp_const<Ty>;
+  };
+
+} // namespace details
 
 template<typename Ty>
-struct underlying_const_type_impl<fp_const<Ty>> {
-  using type = typename fp_const<Ty>::value_t;
-};
+using underlying_const_type =
+    typename details::underlying_const_type_impl<Ty>::type;
 
 template<typename Ty>
-using underlying_const_type = typename underlying_const_type_impl<Ty>::type;
+using to_const_type = typename details::to_const_type_impl<Ty>::type;
 
 } // namespace gal::literals

tests/operations/multiobjective/clustering_tests.cpp

@@ -307,8 +307,10 @@ class hypergird_exact_tests : public hypergird_base_tests {
 };
 
 TEST_F(hypergird_exact_tests, grouped_clusters_count) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.5, 0.5> op;
+  gal::cluster::hypergrid<fitness_t, 0.5_dc, 0.5_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -318,8 +320,10 @@ TEST_F(hypergird_exact_tests, grouped_clusters_count) {
 }
 
 TEST_F(hypergird_exact_tests, grouped_clusters_content) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.5, 0.5> op;
+  gal::cluster::hypergrid<fitness_t, 0.5_dc, 0.5_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -334,8 +338,10 @@ TEST_F(hypergird_exact_tests, grouped_clusters_content) {
 }
 
 TEST_F(hypergird_exact_tests, grouped_clusters_labels) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.5, 0.5> op;
+  gal::cluster::hypergrid<fitness_t, 0.5_dc, 0.5_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -350,8 +356,10 @@ TEST_F(hypergird_exact_tests, grouped_clusters_labels) {
 }
 
 TEST_F(hypergird_exact_tests, unique_clusters_count) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.05, 0.05> op;
+  gal::cluster::hypergrid<fitness_t, 0.05_dc, 0.05_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -361,8 +369,10 @@ TEST_F(hypergird_exact_tests, unique_clusters_count) {
 }
 
 TEST_F(hypergird_exact_tests, unique_clusters_labels) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.05, 0.05> op;
+  gal::cluster::hypergrid<fitness_t, 0.05_dc, 0.05_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -381,8 +391,10 @@ class hypergird_overflow_tests : public hypergird_base_tests {
 };
 
 TEST_F(hypergird_overflow_tests, unique_clusters_count) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.05, 0.05> op;
+  gal::cluster::hypergrid<fitness_t, 0.05_dc, 0.05_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);
@@ -392,8 +404,10 @@ TEST_F(hypergird_overflow_tests, unique_clusters_count) {
 }
 
 TEST_F(hypergird_overflow_tests, unique_clusters_labels) {
+  using namespace gal::literals;
+
   // arrange
-  gal::cluster::hypergrid<fitness_t, 0.05, 0.05> op;
+  gal::cluster::hypergrid<fitness_t, 0.05_dc, 0.05_dc> op;
 
   // act
   auto clusters = op(*population_, pareto_);