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Re: std::max: if versus ?:

From: Paolo Carlini <paolo dot carlini at oracle dot com>
To: libstdc++ at gcc dot gnu dot org
Cc: Marc Glisse <marc dot glisse at inria dot fr>
Date: Thu, 20 Sep 2012 14:29:24 +0200
Subject: Re: std::max: if versus ?:
References: <alpine.DEB.2.02.1209201338430.7104@stedding.saclay.inria.fr> <505B06DB.301@oracle.com> <alpine.DEB.2.02.1209201416040.7104@stedding.saclay.inria.fr>

On 09/20/2012 02:24 PM, Marc Glisse wrote:

When a and b have possibly different types, using "if" makes a lot of sense (I even advocated replacing ?: with "if" somewhere in the gcc codebase in PR50177). Inside std::max, a and b both have exactly the same type const _Tp&, so it shouldn't matter.

Note that libcxx uses ?: for its implementation of std::max.

I assume there are historical reasons, some compilers had bugs in their ?: support or produced slightly faster code with "if"...

Good, good, consider a patch pre-approved ;)

Paolo.

References:
- std::max: if versus ?:
  - From: Marc Glisse
- Re: std::max: if versus ?:
  - From: Paolo Carlini
- Re: std::max: if versus ?:
  - From: Marc Glisse

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