runtime/metrics: add a note about floating-point values to package docs

This change adds a note to the package documentation that the package
will never produce a NaN or infinity, to help ease usability.

Change-Id: I72ff6ab636ca23722a68ef11e707c68b0724ac04
Reviewed-on: https://go-review.googlesource.com/c/go/+/275854
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>

diff --git a/src/runtime/metrics/doc.go b/src/runtime/metrics/doc.go
index 05a887e4f40e240e62e7ddc0ad1e8df2b05dd0e1..a68184ee822c01f186f71c457f686a7bb87d70ec 100644 (file)
--- a/src/runtime/metrics/doc.go
+++ b/src/runtime/metrics/doc.go
@@ -42,6 +42,12 @@ did also, and a new key should be introduced.
 For more details on the precise definition of the metric key's path and unit formats, see
 the documentation of the Name field of the Description struct.
 
+A note about floats
+
+This package supports metrics whose values have a floating-point representation. In
+order to improve ease-of-use, this package promises to never produce the following
+classes of floating-point values: NaN, infinity.
+
 Supported metrics
 
 Below is the full list of supported metrics, ordered lexicographically.