feat: Add Linear Congruential Generator (LCG) implementation for compile-time pseudo-random number generation

Author: weilycoder

weilycoder/const_rand.hpp

@@ -0,0 +1,50 @@
+#ifndef WEILYCODER_CONST_RAND_HPP
+#define WEILYCODER_CONST_RAND_HPP
+
+#include <cstdint>
+
+namespace weilycoder {
+/**
+ * @brief Linear Congruential Generator (LCG) to produce pseudo-random numbers
+ *        at compile-time.
+ * @tparam a The multiplier.
+ * @tparam c The increment.
+ * @tparam m The modulus.
+ * @param state The current state of the generator.
+ * @return The next state of the generator.
+ */
+template <uint32_t a, uint32_t c, uint64_t m>
+constexpr uint32_t &lcg_next(uint32_t &state) {
+  state = (static_cast<uint64_t>(a) * state + c) % m;
+  return state;
+}
+
+/**
+ * @brief LCG using parameters from "Minimal Standard" by Park and Miller.
+ * @param state The current state of the generator.
+ * @return The next state of the generator.
+ */
+constexpr uint32_t &lcg_minstd(uint32_t &state) {
+  return lcg_next<48271, 0, 2147483647>(state);
+}
+
+/**
+ * @brief LCG using parameters from "minstd_rand0" by Park and Miller.
+ * @param state The current state of the generator.
+ * @return The next state of the generator.
+ */
+constexpr uint32_t &lcg_minstd_rand0(uint32_t &state) {
+  return lcg_next<16807, 0, 2147483647>(state);
+}
+
+/**
+ * @brief LCG using parameters from "Numerical Recipes".
+ * @param state The current state of the generator.
+ * @return The next state of the generator.
+ */
+constexpr uint32_t &lcg_nr(uint32_t &state) {
+  return lcg_next<1103515245, 12345, 4294967296>(state);
+}
+} // namespace weilycoder
+
+#endif