Export the Instrument IsEmpty method

CHANGELOG.md

@@ -8,6 +8,11 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- The `Empty` method is added to the `Instrument` type in `go.opentelemetry.io/otel/sdk/metric`.
+  This method is used to check if an `Instrument` instance is a zero-value. (#5431)
+
 ### Fixed
 
 - Log a warning to the OpenTelemetry internal logger when a `Record` in `go.opentelemetry.io/otel/sdk/log` drops an attribute due to a limit being reached. (#5376)

sdk/metric/instrument.go

@@ -77,8 +77,8 @@ type Instrument struct {
 	nonComparable // nolint: unused
 }
 
-// empty returns if all fields of i are their zero-value.
-func (i Instrument) empty() bool {
+// Empty returns if all Instrument fields are their zero-value.
+func (i Instrument) Empty() bool {
 	return i.Name == "" &&
 		i.Description == "" &&
 		i.Kind == zeroInstrumentKind &&

sdk/metric/view.go

@@ -43,7 +43,7 @@ type View func(Instrument) (Stream, bool)
 // of the default. If you need to zero out an Stream field returned from a
 // View, create a View directly.
 func NewView(criteria Instrument, mask Stream) View {
-	if criteria.empty() {
+	if criteria.Empty() {
 		global.Error(
 			errEmptyView, "dropping view",
 			"mask", mask,