Zig 0.17.0-dev (Split by item)

This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig library itself.

wrap

Odd sawtooth function

        |
     /  | /    /
    /   |/    /
 --/----/----/--
  /    /|   /
 /    / |  /
        |

Limit x to the half-open interval [-r, r).

math.wrap

pub fn wrap(x: anytype, r: anytype) @TypeOf(x)

File

lib/std/math.zig:443

Code

pub fn wrap(x: anytype, r: anytype) @TypeOf(x) {
    const info_x = @typeInfo(@TypeOf(x));
    const info_r = @typeInfo(@TypeOf(r));
    if (info_x == .int and info_x.int.signedness != .signed) {
        @compileError("x must be floating point, comptime integer, or signed integer.");
    }
    switch (info_r) {
        .int => {
            // in the rare usecase of r not being comptime_int or float,
            // take the penalty of having an intermediary type conversion,
            // otherwise the alternative is to unwind iteratively to avoid overflow
            const R = @Int(.signed, info_r.int.bits + 1);
            const radius: if (info_r.int.signedness == .signed) @TypeOf(r) else R = r;
            return @intCast(@mod(x - radius, 2 * @as(R, r)) - r); // provably impossible to overflow
        },
        else => {
            return @mod(x - r, 2 * r) - r;
        },
    }
}