zig/test/c/stdlib/drand48.zig

const builtin = @import("builtin");
const std = @import("std");

const c = std.c;
const testing = std.testing;

test "erand48" {
    if (builtin.target.os.tag == .windows) return; // no erand48

    var xsubi: [3]c_ushort = .{ 37174, 64810, 11603 };

    try testing.expectApproxEqAbs(0.8965, c.erand48(&xsubi), 0.0005);
    try testing.expectEqualSlices(c_ushort, &.{ 22537, 47966, 58735 }, &xsubi);

    try testing.expectApproxEqAbs(0.3375, c.erand48(&xsubi), 0.0005);
    try testing.expectEqualSlices(c_ushort, &.{ 37344, 32911, 22119 }, &xsubi);

    try testing.expectApproxEqAbs(0.6475, c.erand48(&xsubi), 0.0005);
    try testing.expectEqualSlices(c_ushort, &.{ 23659, 29872, 42445 }, &xsubi);

    try testing.expectApproxEqAbs(0.5005, c.erand48(&xsubi), 0.0005);
    try testing.expectEqualSlices(c_ushort, &.{ 31642, 7875, 32802 }, &xsubi);

    try testing.expectApproxEqAbs(0.5065, c.erand48(&xsubi), 0.0005);
    try testing.expectEqualSlices(c_ushort, &.{ 64669, 14399, 33170 }, &xsubi);
}

test "jrand48" {
    if (builtin.target.os.tag == .windows) return; // no jrand48

    if (builtin.target.os.tag == .openbsd) return error.SkipZigTest; // TODO

    var xsubi: [3]c_ushort = .{ 25175, 11052, 45015 };

    try testing.expectEqual(1699503220, c.jrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 2326, 23668, 25932 }, &xsubi);

    try testing.expectEqual(-992276007, c.jrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 41577, 4569, 50395 }, &xsubi);

    try testing.expectEqual(-19535776, c.jrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 31936, 59488, 65237 }, &xsubi);

    try testing.expectEqual(79438377, c.jrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 40395, 8745, 1212 }, &xsubi);

    try testing.expectEqual(-1258917728, c.jrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 37242, 28832, 46326 }, &xsubi);
}

test "nrand48" {
    if (builtin.target.os.tag == .windows) return; // no nrand48

    var xsubi: [3]c_ushort = .{ 546, 33817, 23389 };

    try testing.expectEqual(914920692, c.nrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 29829, 10728, 27921 }, &xsubi);

    try testing.expectEqual(754104482, c.nrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 6828, 28997, 23013 }, &xsubi);

    try testing.expectEqual(609453945, c.nrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 58183, 3826, 18599 }, &xsubi);

    try testing.expectEqual(1878644360, c.nrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 36678, 44304, 57331 }, &xsubi);

    try testing.expectEqual(2114923686, c.nrand48(&xsubi));
    try testing.expectEqualSlices(c_ushort, &.{ 58585, 22861, 64542 }, &xsubi);
}