git: 93f7a3023c31 - main - style.9: be explicit about booleans in comparisons

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=93f7a3023c3147d42dbe3dab58a5a70779587ea5

commit 93f7a3023c3147d42dbe3dab58a5a70779587ea5
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2021-05-27 15:25:32 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2024-11-12 17:25:28 +0000

    style.9: be explicit about booleans in comparisons
    
    We prefer something like "if (count != 0)" over "if (count)" for
    non-boolean variables.  This was implicit in examples, but was unclear
    for some new contributors.  Attempt to clarify by providing a more
    explicit statement and example.
    
    Reviewed by:    imp
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D30507
---
 share/man/man9/style.9 | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/share/man/man9/style.9 b/share/man/man9/style.9
index 69561e3e1e73..9bf30370a374 100644
--- a/share/man/man9/style.9
+++ b/share/man/man9/style.9
@@ -746,9 +746,10 @@ not:
 !(p = f())
 .Ed
 .Pp
-Do not use
+Do not test without a comparison, or with unary
 .Ic \&!
-for tests unless it is a boolean, e.g., use:
+(except for booleans).
+For example, use:
 .Bd -literal
 if (*p == '\e0')
 .Ed
@@ -758,6 +759,16 @@ not:
 if (!*p)
 .Ed
 .Pp
+Prefer:
+.Bd -literal
+if (count != 0)
+.Ed
+.Pp
+over:
+.Bd -literal
+if (count)
+.Ed
+.Pp
 Routines returning
 .Vt "void *"
 should not have their return values cast