Package typeutil detects nil through interfaces, obtains zero values generically, dereferences pointers safely, and converts booleans to integers without a branch.
- [IsNil]: reflection-based nil check that handles all nilable kinds (chan,
func, interface, map, pointer, slice, unsafe pointer) and the untyped nil
case, including a nil concrete pointer wrapped in a non-nil interface that
v == nilmisses. - [IsZero]: returns true when the value equals the zero value for its type (empty string, 0, nil pointer, false), without requiring a comparable constraint.
- [Zero]: returns the zero value for any type T.
- [Value]: dereferences a pointer, returning the zero value of T when the pointer is nil.
- [BoolToInt]: converts a bool to 0 or 1 using the pattern the Go compiler optimizes to a single MOVBLZX instruction.
// Nil detection through an interface:
var p *MyStruct
var i any = p
typeutil.IsNil(i) // true, whereas i == nil is false
// Zero value inferred from an existing value, as a sentinel return:
func check[T any](v T) (T, error) {
if !valid(v) {
return typeutil.Zero(v), errInvalid
}
return v, nil
}
// Safe pointer dereference:
var timeout *time.Duration
d := typeutil.Value(timeout) // 0, no panic
// Branch-free bool-to-int:
score += typeutil.BoolToInt(isBonus) * bonusPoints
- Generic code must detect nil through an interface, where == nil is not enough.
- You need the zero value of a type parameter.
var nilChan chan int
v := typeutil.IsNil(nilChan)
fmt.Println(v)
// Output:
// trueFull source is in example_typeutil_test.go. More runnable examples are on pkg.go.dev.
This package reaches no external module: it uses only the Go standard library.