From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id B160A396E02D; Tue, 30 Aug 2022 00:02:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B160A396E02D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1661817742; bh=IN7JLqxui7iu51pr5q1PQuAfWBzwsbJs3LR6iHhlKJA=; h=From:To:Subject:Date:In-Reply-To:References:From; b=H0iNoiNx+ljDAiIhgdbHTz2kFgWBBeQrxVXXB0RtNzDjNc+1YnIJrQPNWoLzoWcmr nvAj/4y9BdwzseQGmHfvHevpmKc/NcKwgthH/cdC/dY9O6ZjaRYZuC6hDKZcwnOwb+ q3k/5/A37CjpsuMiFK3OdwJrZ9agB2dkOhu+g3Ro= From: "f.heckenbach@fh-soft.de" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/106774] warning about comparison to true/false Date: Tue, 30 Aug 2022 00:02:22 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: unknown X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: f.heckenbach@fh-soft.de X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106774 --- Comment #2 from Frank Heckenbach --- This should cover all cases mentioned: void t (bool a, int i, float e, double f) { // Boolean literal comparisons if (a =3D=3D true) // better: if (a) return; if (a =3D=3D false) // better: if (!a) return; if (a !=3D true) // better: if (!a) return; if (a !=3D false) // better: if (a) return; // also reversed to be sure if (true =3D=3D a) // better: if (a) return; if (false !=3D a) // better: if (a) return; // Integer comparisons to Boolean literals if (i =3D=3D true) // better: if (i =3D=3D 1) return; if (i =3D=3D false) // better: if (i =3D=3D 0) or: if (!i) return;=20=20 if (i !=3D true) // better: if (i !=3D 1) return; if (i !=3D false) // better: if (i !=3D 0) or: if (i) return; // Floating-point comparisons to Boolean literals if (e =3D=3D true) // very strange at all, if meant so, then better: if = (e =3D=3D 1.0f) return; if (f =3D=3D false) // very strange at all, if meant so, then better: if= (f =3D=3D 0.0) return; }=