ptr
Generic pointer functions.
Usage
go get github.com/0xch4z/ptr
Why is this even a thing?
ptr.To
There is no function to create a reference to a literal value in Go’s built-ins
or it’s standard library. Before generics, I found myself copy-pasting the same
stringPtr(string) *string, intPtr(int) *int, etc. function declarations in
every code base I started. This is obviously not ideal and gets increasingly less
maintainable as the types of literal values you need to make references to very
and get more complex.
takesOptionalString(&"hi") // illegal
takesOptionalString(aws.String("hi")) // what does AWS have to do with this???
func strPtr(s string) *string { return &s }; takesOptionalString(strPtr("hi")) // unmaintainable
takesOptionalInt(ptr.From(5)) // noice
ptr.ValueFrom
Another frustration is that while Go makes it easy to handle missing input data with zero-values for all types in the language, there is no mechanism for safely dereferencing a pointer if it’s not nil or interpreting the absence of value as a zero-value.
type QueryOptions struct { Page *int } // pretend we don't maintain this struct
var opts QueryOptions
var page int
page = *opts.Page // might panic
if opts.Page != nil { page = *opts.Page } // clunky
page = ptr.ValueFrom(opts.Page) // noice
