typeutil.go

/*
Package typeutil contains a collection of type-related generic utility
functions.

This package provides a set of utility functions and definitions for working
with generic types in Go.
*/
package typeutil

import (
	"reflect"
)

// IsNil returns true if the input value is nil.
func IsNil(v any) bool {
	if v == nil {
		return true
	}

	value := reflect.ValueOf(v)

	switch value.Kind() { //nolint:exhaustive
	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Pointer, reflect.Slice, reflect.UnsafePointer:
		return value.IsNil()
	}

	return false
}

// IsZero returns true if the input value is equal to the zero instance (e.g. empty string, 0 int, nil pointer).
func IsZero[T any](v T) bool {
	return reflect.ValueOf(&v).Elem().IsZero()
}

// Zero returns the zero instance (e.g. empty string, 0 int, nil pointer).
func Zero[T any](_ T) T {
	var zero T
	return zero
}

// Pointer returns the address of v.
func Pointer[T any](v T) *T {
	return &v
}

// Value returns the value of the provided pointer or the type default (zero value) if nil.
func Value[T any](p *T) T {
	if IsNil(p) {
		var zero T
		return zero
	}

	return *p
}

// BoolToInt converts a boolean value to an integer.
//
// NOTE: this is currently the fastest implementation as it will be optimized by
// the compiler with a MOVBLZX instruction.
// Ref.:
//   - https://0x0f.me/blog/golang-compiler-optimization/
//   - https://github.com/golang/go/issues/6011
func BoolToInt(b bool) int {
	var i int

	if b {
		i = 1
	} else {
		i = 0
	}

	return i
}