go-pointer

A simple, type-safe Go utility library for working with pointers using generics.

Features

• Type-safe pointer operations using Go generics
• Zero dependencies
• Simple API with only three functions
• Well-documented with examples

Installation

go get github.com/sergei-bronnikov/go-pointer

Usage

import "github.com/sergei-bronnikov/go-pointer"

ToPointer

Convert any value to a pointer. Useful when you need to pass a pointer to a literal or computed value.

// Convert string literal to pointer
name := gopointer.ToPointer("John Doe")
fmt.Println(*name) // Output: John Doe

// Convert number to pointer
age := gopointer.ToPointer(42)
fmt.Println(*age) // Output: 42

// Useful for optional struct fields
type User struct {
    Name  string
    Email *string
}

user := User{
    Name:  "John",
    Email: gopointer.ToPointer("john@example.com"),
}

ToValue

Dereference a pointer to get its value. Note: This function will panic if the pointer is nil.

str := "hello"
ptr := &str
value := gopointer.ToValue(ptr)
fmt.Println(value) // Output: hello

ToValueOrDefault

Safely dereference a pointer with a fallback default value if the pointer is nil.

// With nil pointer
var ptr *string = nil
value := gopointer.ToValueOrDefault(ptr, "default")
fmt.Println(value) // Output: default

// With non-nil pointer
str := "hello"
ptr = &str
value = gopointer.ToValueOrDefault(ptr, "default")
fmt.Println(value) // Output: hello

// Useful for working with optional API fields
type Config struct {
    Timeout *int
}

cfg := Config{}
timeout := gopointer.ToValueOrDefault(cfg.Timeout, 30)
fmt.Println(timeout) // Output: 30

Complete Example

package main

import (
    "fmt"
    "github.com/sergei-bronnikov/go-pointer"
)

type UserProfile struct {
    Username string
    Email    *string
    Age      *int
}

func main() {
    // Create profile with optional fields
    profile := UserProfile{
        Username: "johndoe",
        Email:    gopointer.ToPointer("john@example.com"),
        Age:      nil,
    }

    // Safely access optional fields
    email := gopointer.ToValueOrDefault(profile.Email, "no-email@example.com")
    age := gopointer.ToValueOrDefault(profile.Age, 0)

    fmt.Printf("Username: %s\n", profile.Username)
    fmt.Printf("Email: %s\n", email)
    fmt.Printf("Age: %d\n", age)
}

API Reference

ToPointer[T any](value T) *T

Converts a value of any type to a pointer to that value.

Parameters:

• value: The value to convert to a pointer

Returns:

• A pointer to the value

ToValue[T any](pointer *T) T

Dereferences a pointer and returns its value.

Parameters:

• pointer: The pointer to dereference

Returns:

• The dereferenced value

Note: Panics if the pointer is nil.

ToValueOrDefault[T any](pointer *T, defaultValue T) T

Safely dereferences a pointer, returning a default value if the pointer is nil.

Parameters:

• pointer: The pointer to dereference
• defaultValue: The value to return if the pointer is nil

Returns:

• The dereferenced value, or the default value if the pointer is nil

Requirements

• Go 1.18 or higher (for generics support)

License

See LICENSE file for details.