If the compiler is good the assignment is elided indeed, that's not what I meant to point out.
On Thu, 28 May 2015 at 22:17 Andres Freund <and...@anarazel.de> wrote: > On 2015-05-28 20:14:33 +0000, Gaetano Mendola wrote: > > src/backend/commands/explain.c:1692 > > src/backend/commands/explain.c:1874 > > src/backend/commands/explain.c:1986 > > > > there is the following assignment: > > > > ancestors = list_delete_first(ancestors); > > > > but it has no effect at all being that a function parameter and not used > > anymore after the assignment itself. > > So? It costs little to nothing, and it'll make it much less likely that > a stale version of 'ancestors' is used when the code is expanded. > > Greetings, > > Andres Freund >