text/template: documentation for IsTrue disagrees with its implementation for struct types

[bcmills]

As noted in #28391, the documentation for template.IsTrue says:

IsTrue reports whether the value is 'true', in the sense of not the zero of its type, and whether the value has a meaningful truth value.

The zero time.Time is the zero of its type, so according to the documentation it should be considered to be true, but the implementation clearly intends otherwise:

go/src/text/template/exec.go

Lines 326 to 327 in f6b554f

	case reflect.Struct:
	truth = true // Struct values are always true.

Either the documentation should be clarified, or the behavior of IsTrue should be fixed to match what is documented. Probably the former.

[bcmills]

CC: @robpike @mvdan

[mvdan]

Struct values have always been true in the implementation since 2011: 1adda46

So I'd agree that this is a minor documentation issue.

[gopherbot]

Change https://golang.org/cl/144657 mentions this issue: text/template: clarify truthiness of structs

[rsc]

If the decision was document or fix, document it. As @mvdan says, it's been that way for a long time. It's not worth a semantic change.

[mvdan]

@robpike given that you've self-assigned this - do you want me to abandon my CL?