feat(std.Random): add a linear congruent generator

lib/std/Random.zig

@@ -26,6 +26,7 @@ pub const Sfc64 = @import("Random/Sfc64.zig");
 pub const RomuTrio = @import("Random/RomuTrio.zig");
 pub const SplitMix64 = @import("Random/SplitMix64.zig");
 pub const ziggurat = @import("Random/ziggurat.zig");
+pub const lcg = @import("Random/lcg.zig");
 
 /// Any comparison of this field may result in illegal behavior, since it may be set to
 /// `undefined` in cases where the random implementation does not have any associated

lib/std/Random/lcg.zig

@@ -0,0 +1,28 @@
+//! Linear congruential generator
+//!
+//! X(n+1) = (a * Xn + c) mod m
+//!
+//! PRNG
+
+const std = @import("std");
+
+/// Linear congruent generator where the modulo is `std.math.maxInt(T)`,
+/// wrapping over the integer.
+pub fn Wrapping(comptime T: type) type {
+    return struct {
+        xi: T,
+        a: T,
+        c: T,
+
+        pub fn init(xi: T, a: T, c: T) LcgSelf {
+            return .{ .xi = xi, .a = a, .c = c };
+        }
+
+        pub fn next(lcg: *LcgSelf) T {
+            lcg.xi = (lcg.a *% lcg.xi) +% lcg.c;
+            return lcg.xi;
+        }
+
+        const LcgSelf = @This();
+    };
+}