    const std = @import("../std.zig");
    const testing = std.testing;
    const math = std.math;

    pub const abs = @import("complex/abs.zig").abs;
    pub const acosh = @import("complex/acosh.zig").acosh;
    pub const acos = @import("complex/acos.zig").acos;
    pub const arg = @import("complex/arg.zig").arg;
    pub const asinh = @import("complex/asinh.zig").asinh;
    pub const asin = @import("complex/asin.zig").asin;
    pub const atanh = @import("complex/atanh.zig").atanh;
    pub const atan = @import("complex/atan.zig").atan;
    pub const conj = @import("complex/conj.zig").conj;
    pub const cosh = @import("complex/cosh.zig").cosh;
    pub const cos = @import("complex/cos.zig").cos;
    pub const exp = @import("complex/exp.zig").exp;
    pub const log = @import("complex/log.zig").log;
    pub const pow = @import("complex/pow.zig").pow;
    pub const proj = @import("complex/proj.zig").proj;
    pub const sinh = @import("complex/sinh.zig").sinh;
    pub const sin = @import("complex/sin.zig").sin;
    pub const sqrt = @import("complex/sqrt.zig").sqrt;
    pub const tanh = @import("complex/tanh.zig").tanh;
    pub const tan = @import("complex/tan.zig").tan;

    /// A complex number consisting of a real an imaginary part. T must be a floating-point value.
    pub fn Complex(comptime T: type) type {
        return struct {
            const Self = @This();

            /// Real part.
            re: T,

            /// Imaginary part.
            im: T,

            /// Create a new Complex number from the given real and imaginary parts.
            pub fn init(re: T, im: T) Self {
                return Self{
                    .re = re,
                    .im = im,
                };
            }

            /// Returns the sum of two complex numbers.
            pub fn add(self: Self, other: Self) Self {
                return Self{
                    .re = self.re + other.re,
                    .im = self.im + other.im,
                };
            }

            /// Returns the subtraction of two complex numbers.
            pub fn sub(self: Self, other: Self) Self {
                return Self{
                    .re = self.re - other.re,
                    .im = self.im - other.im,
                };
            }

            /// Returns the product of two complex numbers.
            pub fn mul(self: Self, other: Self) Self {
                return Self{
                    .re = self.re * other.re - self.im * other.im,
                    .im = self.im * other.re + self.re * other.im,
                };
            }

            /// Returns the quotient of two complex numbers.
            pub fn div(self: Self, other: Self) Self {
                const re_num = self.re * other.re + self.im * other.im;
                const im_num = self.im * other.re - self.re * other.im;
                const den = other.re * other.re + other.im * other.im;

                return Self{
                    .re = re_num / den,
                    .im = im_num / den,
                };
            }

            /// Returns the complex conjugate of a number.
            pub fn conjugate(self: Self) Self {
                return Self{
                    .re = self.re,
                    .im = -self.im,
                };
            }

            /// Returns the negation of a complex number.
            pub fn neg(self: Self) Self {
                return Self{
                    .re = -self.re,
                    .im = -self.im,
                };
            }

            /// Returns the product of complex number and i=sqrt(-1)
            pub fn mulbyi(self: Self) Self {
                return Self{
                    .re = -self.im,
                    .im = self.re,
                };
            }

            /// Returns the reciprocal of a complex number.
            pub fn reciprocal(self: Self) Self {
                const m = self.re * self.re + self.im * self.im;
                return Self{
                    .re = self.re / m,
                    .im = -self.im / m,
                };
            }

            /// Returns the magnitude of a complex number.
            pub fn magnitude(self: Self) T {
                return @sqrt(self.re * self.re + self.im * self.im);
            }
        };
    }

    const epsilon = 0.0001;

    test "complex.add" {
        const a = Complex(f32).init(5, 3);
        const b = Complex(f32).init(2, 7);
        const c = a.add(b);

        try testing.expect(c.re == 7 and c.im == 10);
    }

    test "complex.sub" {
        const a = Complex(f32).init(5, 3);
        const b = Complex(f32).init(2, 7);
        const c = a.sub(b);

        try testing.expect(c.re == 3 and c.im == -4);
    }

    test "complex.mul" {
        const a = Complex(f32).init(5, 3);
        const b = Complex(f32).init(2, 7);
        const c = a.mul(b);

        try testing.expect(c.re == -11 and c.im == 41);
    }

    test "complex.div" {
        const a = Complex(f32).init(5, 3);
        const b = Complex(f32).init(2, 7);
        const c = a.div(b);

        try testing.expect(math.approxEqAbs(f32, c.re, @as(f32, 31) / 53, epsilon) and
            math.approxEqAbs(f32, c.im, @as(f32, -29) / 53, epsilon));
    }

    test "complex.conjugate" {
        const a = Complex(f32).init(5, 3);
        const c = a.conjugate();

        try testing.expect(c.re == 5 and c.im == -3);
    }

    test "complex.neg" {
        const a = Complex(f32).init(5, 3);
        const c = a.neg();

        try testing.expect(c.re == -5 and c.im == -3);
    }

    test "complex.mulbyi" {
        const a = Complex(f32).init(5, 3);
        const c = a.mulbyi();

        try testing.expect(c.re == -3 and c.im == 5);
    }

    test "complex.reciprocal" {
        const a = Complex(f32).init(5, 3);
        const c = a.reciprocal();

        try testing.expect(math.approxEqAbs(f32, c.re, @as(f32, 5) / 34, epsilon) and
            math.approxEqAbs(f32, c.im, @as(f32, -3) / 34, epsilon));
    }

    test "complex.magnitude" {
        const a = Complex(f32).init(5, 3);
        const c = a.magnitude();

        try testing.expect(math.approxEqAbs(f32, c, 5.83095, epsilon));
    }

    test "complex.cmath" {
        _ = @import("complex/abs.zig");
        _ = @import("complex/acosh.zig");
        _ = @import("complex/acos.zig");
        _ = @import("complex/arg.zig");
        _ = @import("complex/asinh.zig");
        _ = @import("complex/asin.zig");
        _ = @import("complex/atanh.zig");
        _ = @import("complex/atan.zig");
        _ = @import("complex/conj.zig");
        _ = @import("complex/cosh.zig");
        _ = @import("complex/cos.zig");
        _ = @import("complex/exp.zig");
        _ = @import("complex/log.zig");
        _ = @import("complex/pow.zig");
        _ = @import("complex/proj.zig");
        _ = @import("complex/sinh.zig");
        _ = @import("complex/sin.zig");
        _ = @import("complex/sqrt.zig");
        _ = @import("complex/tanh.zig");
        _ = @import("complex/tan.zig");
    }