implement

.gitignore

@@ -1,15 +1,2 @@
-# Binaries for programs and plugins
-*.exe
-*.exe~
-*.dll
-*.so
-*.dylib
-
-# Test binary, built with `go test -c`
-*.test
-
-# Output of the go coverage tool, specifically when used with LiteIDE
-*.out
-
-# Dependency directories (remove the comment below to include it)
-# vendor/
+.idea/
+vendor/

README.md

@@ -1,2 +1,27 @@
 # ptr
 Simple pointer helpers for Go
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/candiduslynx/ptr.svg)](https://pkg.go.dev/github.com/candiduslynx/ptr)
+
+## Obtaining pointer to the value
+
+Simply pass the value to the `To` function, the type will be inferred by the Go compiler.
+
+```go
+p := ptr.To(float32(0.5)) // p is *float32 pointing to the value 0.5
+```
+
+## Retrieving value designated by pointer
+
+To retrieve the value designated by pointer simply pass the pointer to `From` function.
+If the pointer might be `nil` you can supply optional default value as well.
+if the pointer is nil and default value isn't provided, `From` will panic.
+
+```go
+// panics
+_ = ptr.From((*float32)(nil))
+
+var vv = floaat32(0.5)
+value = ptr.From(&vv) // value = float32(0.5)
+value = ptr.From((*float32)(nil), 0.7) // value = float32(0.7)
+```

go.mod

@@ -0,0 +1,11 @@
+module github.com/candiduslynx/ptr
+
+go 1.18
+
+require github.com/stretchr/testify v1.8.1
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,17 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

ptr.go

@@ -0,0 +1,15 @@
+// Package ptr implements a simple pointer instrumentation.
+// As it is based on Go generics, the minimal Go version is 1.18.
+package ptr
+
+// From will extract a value designated by pointer provider.
+// It will panic if the pointer provided is nil and the default isn't supplied.
+func From[T any](pointer *T, dflt ...T) T {
+	if pointer == (*T)(nil) && len(dflt) > 0 {
+		return dflt[0]
+	}
+	return *pointer
+}
+
+// To will return a link to the value.
+func To[T any](value T) (pointer *T) { return &value }

ptr_test.go

@@ -0,0 +1,39 @@
+package ptr_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/candiduslynx/ptr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFrom(t *testing.T) {
+	require.IsType(t, 0, ptr.From(new(int)))
+	require.IsType(t, int32(0), ptr.From(new(int32)))
+	require.IsType(t, int64(0), ptr.From(new(int64)))
+	require.IsType(t, struct{}{}, ptr.From(new(struct{})))
+	require.IsType(t, time.Time{}, ptr.From(new(time.Time)))
+	require.IsType(t, new(time.Time), ptr.From(new(*time.Time)))
+}
+
+func TestFrom_Panics(t *testing.T) {
+	require.Panics(t, func() {
+		ptr.From((*float32)(nil))
+	})
+}
+
+func TestFrom_NotPanics(t *testing.T) {
+	require.NotPanics(t, func() {
+		ptr.From((*float32)(nil), 0)
+	})
+}
+
+func TestTo(t *testing.T) {
+	require.IsType(t, new(int), ptr.To(0))
+	require.IsType(t, new(int32), ptr.To(int32(0)))
+	require.IsType(t, new(int64), ptr.To(int64(0)))
+	require.IsType(t, new(struct{}), ptr.To(struct{}{}))
+	require.IsType(t, new(time.Time), ptr.To(time.Time{}))
+	require.IsType(t, new(*time.Time), ptr.To(new(time.Time)))
+}