# Equivalent of c\\c++ compiler directives in Julia

**URL:** <https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480>\
**Category:** New to Julia\
**Tags:** question\
**Created:** [April 22, 2018, 1:38pm UTC](https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480 "2018-04-22T13:38:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![alirezamecheng](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@alirezamecheng](https://discourse.julialang.org/u/alirezamecheng)\
**Post date:** [April 22, 2018, 1:38pm UTC](https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480/1 "2018-04-22T13:38:34Z")

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Hello,

using compiler directives like

```julia
#if A
some instructions 
#elseif B
some instructions
#end

```

In c\c++ language one can tell the compiler to ignore some parts of code under some conditions. I`m curious about to know if there is an equivalent of this future in Julia language.

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [April 22, 2018, 1:46pm UTC](https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480/2 "2018-04-22T13:46:15Z")

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> [@alirezamecheng](#):
>
> In c\c++ language one can tell the compiler to ignore some parts of code under some conditions. I`m curious about to know if there is an equivalent of this future in Julia language.

`@static if`. In many cases (if the compiler has enough information), it will automatically do the if statement at compilation time (and this is helped by automatic function specialization and multiple dispatch). Otherwise, at the top level you can force it via `@static if`.

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<div class="post-metadata">

**Author:** ![alirezamecheng](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@alirezamecheng](https://discourse.julialang.org/u/alirezamecheng)\
**Post date:** [April 22, 2018, 2:10pm UTC](https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480/4 "2018-04-22T14:10:32Z")

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Thank you.

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**Author:** ![yuyichao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yuyichao/32/20_2.png) [@yuyichao](https://discourse.julialang.org/u/yuyichao)\
**Post date:** [April 22, 2018, 2:30pm UTC](https://discourse.julialang.org/t/equivalent-of-c-c-compiler-directives-in-julia/10480/5 "2018-04-22T14:30:55Z")

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> [@ChrisRackauckas](#):
>
> the top level you can force it via @static if.

You usually don’t need it at toplevel.