// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package math

// Abs returns the absolute value of x.
//
// Special cases are:
//
//	Abs(±Inf) = +Inf
//	Abs(NaN) = NaN
func Abs(x float64) float64 {
	return Float64frombits(Float64bits(x) &^ (1 << 63))

// complex numbers. Special case handling conforms to the C99 standard
// Annex G IEC 60559-compatible complex arithmetic.
package cmplx

import "math"

// Abs returns the absolute value (also called the modulus) of x.

	if x.neg == y.neg {
		// x + y == x + y
		// (-x) + (-y) == -(x + y)
		z.abs = z.abs.add(x.abs, y.abs)
	} else {
		// x + (-y) == x - y == -(y - x)
		// (-x) + y == y - x == -(x - y)
		if x.abs.cmp(y.abs) >= 0 {
			z.abs = z.abs.sub(x.abs, y.abs)
		} else {
			neg = !neg
			z.abs = z.abs.sub(y.abs, x.abs)
		}
	}
	z.neg = len(z.abs) > 0 && neg // 0 has no sign
	return z
}

		// a squared Rat is positive and can't be reduced (no need to call norm())
		z.a.neg = false
		z.a.abs = z.a.abs.sqr(x.a.abs)
		if len(x.b.abs) == 0 {
			z.b.abs = z.b.abs.setWord(1)
		} else {
			z.b.abs = z.b.abs.sqr(x.b.abs)
		}
		return z
	}
	z.a.Mul(&x.a, &y.a)
	z.b.abs = mulDenom(z.b.abs, x.b.abs, y.b.abs)
	return z.norm()
}

// Quo sets z to the quotient x/y and returns z.

func (MyMer) String() string {
	return "aa"
}

// Parameterized interface
type Abs[T any] interface {
	Abs() T
}

func G[T Abs[U], U any](t T) {
	T.Abs(t)
	t.Abs()
}

type MyInt int
func (m MyInt) Abs() MyInt {
	if m < 0 {
		return -m
	}
	return m
}

type Abs2 interface {
	Abs() MyInt
}


func main() {
	mm := MyMer(3)
	ms := struct{ Mer }{Mer: mm }

	// For example, the sample code starts with:
	//	p := int(a) + int(b) - int(c)
	//	pa := abs(p - int(a))
	// but the optimized form uses fewer arithmetic operations:
	//	pa := int(b) - int(c)
	//	pa = abs(pa)
	pc := int(c)
	pa := int(b) - pc
	pb := int(a) - pc
	pc = abs(pa + pb)
	pa = abs(pa)
	pb = abs(pb)
	if pa <= pb && pa <= pc {
		return a
	} else if pb <= pc {
		return b
	}
	return c
}

func AbsFile(dir, file, rewrites string) string {
	abs := file
	if dir != "" && !filepath.IsAbs(file) {
		abs = filepath.Join(dir, file)
	}

	abs, rewritten := ApplyRewrites(abs, rewrites)
	if !rewritten && buildcfg.GOROOT != "" && hasPathPrefix(abs, buildcfg.GOROOT) {
		abs = "$GOROOT" + abs[len(buildcfg.GOROOT):]
	}

	// Rewrite paths to match the slash convention of the target.

	}
	return r
}

// NumericAbs matches numeric types with an Abs method.
type NumericAbs[T any] interface {
	Numeric

	Abs() T
}

// AbsDifference computes the absolute value of the difference of
// a and b, where the absolute value is determined by the Abs method.
func AbsDifference[T NumericAbs](a, b T) T {
	d := a - b
	return d.Abs()
}

func (x *Rat) GobEncode() ([]byte, error) {
	if x == nil {
		return nil, nil
	}
	buf := make([]byte, 1+4+(len(x.a.abs)+len(x.b.abs))*_S) // extra bytes for version and sign bit (1), and numerator length (4)
	i := x.b.abs.bytes(buf)
	j := x.a.abs.bytes(buf[:i])
	n := i - j
	if int(uint32(n)) != n {
		// this should never happen
		return nil, errors.New("Rat.GobEncode: numerator too large")
	}

	}
	return r
}

// NumericAbs matches numeric types with an Abs method.
type NumericAbs[T any] interface {
	Numeric

	Abs() T
}

// AbsDifference computes the absolute value of the difference of
// a and b, where the absolute value is determined by the Abs method.
func AbsDifference[T NumericAbs[T]](a, b T) T {
	d := a - b
	return d.Abs()
}