math/big: make ErrNaN actually implement the error interface (oversight)

griesemer · griesemer · commit b28802d2f1ba · 2015-04-08T19:47:39.000Z
There was no way to get to the error message before. Change-Id: I4aa9d3d9f468c33f9996295bafcbed097de0389f Reviewed-on: https://go-review.googlesource.com/8660 Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/src/math/big/float.go b/src/math/big/float.go
@@ -71,6 +71,11 @@ type ErrNaN struct {
 	msg string
 }
 
+// ErrNan implements the error interface.
+func (err ErrNaN) Error() string {
+	return err.msg
+}
+
 // NewFloat allocates and returns a new Float set to x,
 // with precision 53 and rounding mode ToNearestEven.
 // NewFloat panics with ErrNaN if x is a NaN.
diff --git a/src/math/big/float_test.go b/src/math/big/float_test.go
@@ -12,6 +12,9 @@ import (
 	"testing"
 )
 
+// Verify that ErrNaN implements the error interface.
+var _ error = ErrNaN{}
+
 func (x *Float) uint64() uint64 {
 	u, acc := x.Uint64()
 	if acc != Exact {

Original file line number	Diff line number	Diff line change
`@@ -12,6 +12,9 @@ import (`
`12`	`12`	`"testing"`
`13`	`13`	`)`
`14`	`14`
	`15`	`+// Verify that ErrNaN implements the error interface.`
	`16`	`+var _ error = ErrNaN{}`
	`17`	`+`
`15`	`18`	`func (x *Float) uint64() uint64 {`
`16`	`19`	`u, acc := x.Uint64()`
`17`	`20`	`if acc != Exact {`