type Counter interface {
	// Add records a change to the counter.
	Add(ctx context.Context, incr float64, attrs ...attribute.KeyValue)

	instrument.Synchronous
}

type Histogram interface {
	// Record adds an additional value to the distribution.
	Record(ctx context.Context, incr float64, attrs ...attribute.KeyValue)

	instrument.Synchronous
}

type InstrumentProvider interface {
	// Counter creates an instrument for recording increasing values.
	Counter(name string, opts ...instrument.Option) (Counter, error)
	// UpDownCounter creates an instrument for recording changes of a value.
	UpDownCounter(name string, opts ...instrument.Option) (UpDownCounter, error)
	// Histogram creates an instrument for recording a distribution of values.
	Histogram(name string, opts ...instrument.Option) (Histogram, error)
}

type UpDownCounter interface {
	// Add records a change to the counter.
	Add(ctx context.Context, incr float64, attrs ...attribute.KeyValue)

	instrument.Synchronous
}