The maximum value for float64 and complex128 type in Go

i need to know the maximum value of float64 and complex128 variable types in golang. go doesn't seem to have an equivalent of float.h and i don't know how to calculate it.

For example,

package main

import (
	"fmt"
	"math"
)

func main() {
	const f = math.MaxFloat64
	fmt.Printf("%[1]T %[1]v\n", f)
	const c = complex(math.MaxFloat64, math.MaxFloat64)
	fmt.Printf("%[1]T %[1]v\n", c)
}

Output:

float64 1.7976931348623157e+308
complex128 (1.7976931348623157e+308+1.7976931348623157e+308i)

> Package math
>
> import "math"
>
> Floating-point limit values. Max is the largest finite value
> representable by the type. SmallestNonzero is the smallest positive,
> non-zero value representable by the type.
>
> const (
> MaxFloat32 = 3.40282346638528859811704183484516925440e+38 // 2127 * (224 - 1) / 223
> SmallestNonzeroFloat32 = 1.401298464324817070923729583289916131280e-45 // 1 / 2(127 - 1 + 23)
>
> MaxFloat64 = 1.797693134862315708145274237317043567981e+308 // 21023 * (253 - 1) / 252
> SmallestNonzeroFloat64 = 4.940656458412465441765687928682213723651e-324 // 1 / 2(1023 - 1 + 52)
> )

> The Go Programming Language Specification
>
> Numeric types
>
> A numeric type represents sets of integer or floating-point values.
> The predeclared architecture-independent numeric types are:
>
> uint8 the set of all unsigned 8-bit integers (0 to 255)
> uint16 the set of all unsigned 16-bit integers (0 to 65535)
> uint32 the set of all unsigned 32-bit integers (0 to 4294967295)
> uint64 the set of all unsigned 64-bit integers (0 to 18446744073709551615)
>
> int8 the set of all signed 8-bit integers (-128 to 127)
> int16 the set of all signed 16-bit integers (-32768 to 32767)
> int32 the set of all signed 32-bit integers (-2147483648 to 2147483647)
> int64 the set of all signed 64-bit integers (-9223372036854775808 to 9223372036854775807)
>
> float32 the set of all IEEE-754 32-bit floating-point numbers
> float64 the set of all IEEE-754 64-bit floating-point numbers
>
> complex64 the set of all complex numbers with float32 real and imaginary parts
> complex128 the set of all complex numbers with float64 real and imaginary parts
>
> byte alias for uint8
> rune alias for int32
>
> The value of an n-bit integer is n bits wide and represented using
> two's complement arithmetic.
>
> There is also a set of predeclared numeric types with
> implementation-specific sizes:
>
> uint either 32 or 64 bits
> int same size as uint
> uintptr an unsigned integer large enough to store the uninterpreted bits of a pointer value
>
> To avoid portability issues all numeric types are distinct except
> byte, which is an alias for uint8, and rune, which is an alias for
> int32. Conversions are required when different numeric types are mixed
> in an expression or assignment. For instance, int32 and int are not
> the same type even though they may have the same size on a particular
> architecture.

You can also consider using the Inf method from the math package which
returns a value for infinity (positive or negative if you want), but is considered to be float64.

Not too sure if there is an argument for one or the other between math.MaxFloat64 and math.Inf(). Comparing the two I've found that Go interprets the infinity values to be larger than the max float ones.

package main

import (
	"fmt"
	"math"
)

func main() {
	infPos := math.Inf(1) // gives positive infinity
	fmt.Printf("%[1]T %[1]v\n", infPos)
	
	infNeg := math.Inf(-1) // gives negative infinity
	fmt.Printf("%[1]T %[1]v\n", infNeg)
}