TLDR; When is it interesting to “store” field values as static parameters instead of struct fields? as in struct test{fieldA #= This is a Tuple{Int,Int}=#} fieldB::Vector{Int} end vs struct test fieldA::Tuple{Int,Int} fieldB::Vector{Int} end The background for this question: I’ve c…

[image] favba: When is it interesting to “store” field values as static parameters instead of struct fields? Usually never. The goal here is to get as much information at compile time. However, when you do this every single test is a different type (since the concrete types are the parameteri…

I should’ve made it clear. In my case I have a simulation struct. I’ll never have an array of simulations. I build one simulation struct and call run_simulation(my_simulation) and that will be it (running for hours). My example was indeed totally different from my use case. I don’t have any type st…

But you are right: just benchmark the damn thing. :smile:

[image] favba: I’m trying to make this code as fast as (could it be faster??) my advisor’s highly optimized C++ code. I am considered an heretic here in the lab for not using C++ :smile: That’s wonderful! From my experience, it can be at least as fast as C/C++, which isn’t saying a little! …

[image] favba: The information I talking about are the simulations parameters, don’t truly don’t change during the simulation. Grid points, fluid viscosity, wavenumbers … Julia v0.7 will do constant propogation on literals passed into functions and will specialize compilation based on those c…

My hope is that by moving all that information to compile time, which cannot be done in C++, I’d give Julia a head start to beat C++. It is almost as using Julia as a code generator, generating very specific code for every problem that I feed it. If i’m not mistaken that is the trick of FFTW, compu…

@ChrisRackauckas is spot on. I would summarize some things you want to consider when deciding if a value should possibly be a type parameter: Does dispatching on this value make sense? Would it be better/easier to just look at the value at runtime with conditionals or indexing? Don’t get too fanc…

See also [image] Overhead of dynamic dispatch? General Usage There are a number of downsides to encoding a property of your thing in the type system: There will be more time spent in compilation — every time a different type hits a different function, Julia will compile…

Rules of thumb for choosing between storing information as struct field or static parameters

General Usage Performance

mbauman April 6, 2018, 7:04pm 9

Topic		Replies	Views
Improving performance due to setting types of the fields of a struct Performance	10	1260	July 12, 2019
Long parameter for type seems very slow General Usage performance , parametric-types	18	1215	June 22, 2021
Unexpected performance outcome. Does accessing struct members cause allocation? General Usage performance	18	504	October 16, 2024
Const variables New to Julia constants	29	16374	July 13, 2020
Optimising switching algorithms based on value of struct field General Usage performance , struct , type-stability	19	802	July 21, 2022

Rules of thumb for choosing between storing information as struct field or static parameters

Related topics