spacefillr v0.3.3: Add support for use as rng in C++ random interface

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: spacefillr
 Type: Package
 Title: Space-Filling Random and Quasi-Random Sequences
-Version: 0.3.2
+Version: 0.3.3
 Authors@R: c(person("Tyler", "Morgan-Wall", email = "tylermw@gmail.com", 
     role = c("aut", "cph", "cre"), comment = c(ORCID = "0000-0002-3131-3814")),
     person("Andrew", "Helmer", role = c("ctb", "cph")),

inst/include/rng.h

@@ -6,12 +6,18 @@
 #include "pcg/pcg_random.hpp"
 
 class random_gen {
-  public:
-    random_gen(unsigned int seed) : rng(seed) {}
-  random_gen() : rng(pcg_extras::seed_seq_from<std::random_device>{}) { }
+public:
+  // Define result_type for compatibility with standard library requirements
+  using result_type = uint32_t;
+
+  random_gen(unsigned int seed) : rng(seed) {}
+  random_gen() : rng(pcg_extras::seed_seq_from<std::random_device>{}) {}
+
+  // The uniform random number generator function
   float unif_rand() {
-    return(std::ldexp(rng(),-32));
+    return std::ldexp(rng(), -32);
   }
+
   uint32_t UniformUInt32(uint32_t b) {
     uint32_t threshold = (~b + 1u) % b;
     while (true) {
@@ -20,9 +26,22 @@ class random_gen {
         return r % b;
     }
   }
-  pcg32 rng;
 
-};
+  // Call operator to satisfy UniformRandomBitGenerator requirements
+  result_type operator()() {
+    return rng();
+  }
 
+  // Static methods to satisfy UniformRandomBitGenerator requirements
+  static constexpr result_type min() {
+    return pcg32::min();
+  }
+
+  static constexpr result_type max() {
+    return pcg32::max();
+  }
+
+  pcg32 rng;
+};
 
 #endif