reflect2

reflect2

reflect api that avoids runtime reflect.Value cost

• reflect get/set interface{}, with type checking
• reflect get/set unsafe.Pointer, without type checking
• reflect2.TypeByName works like Class.forName found in java

json-iterator use this package to save runtime dispatching cost. This package is designed for low level libraries to optimize reflection performance. General application should still use reflect standard library.

reflect2.TypeByName

// given package is github.com/your/awesome-package
type MyStruct struct {
	// ...
}

// will return the type
reflect2.TypeByName("awesome-package.MyStruct")
// however, if the type has not been used
// it will be eliminated by compiler, so we can not get it in runtime

reflect2 get/set interface{}

valType := reflect2.TypeOf(1)
i := 1
j := 10
valType.Set(&i, &j)
// i will be 10

reflect2 get/set unsafe.Pointer

valType := reflect2.TypeOf(1)
i := 1
j := 10
valType.UnsafeSet(unsfae.Pointer(&i), unsafe.Pointer(&j))
// i will be 10