What do @_inline_meta and @_propagate_inbounds_meta do?

[Davide Lasagna]

Hi, 

code in abstractarray.jl (master) is filled with calls to @_inline_meta and @_propagate_inbounds_meta. Can someone explain what do these to macro do? 

Thanks!

[Kristoffer Carlsson]

I believe they insert the corresponding Meta node into the AST before the actual macros (like @inline) have been defined.

[Davide Lasagna]

Thanks Kristoffer. AFAIU these are not supposed to be used in user code. However, the follow up question is what is a meta node?

[Blake Johnson]

Those macros are used in abstractarray.jl because at the point in the boostrapping process where that file is loaded, we do not yet have access to @inbounds and @propagate_inbounds.

A meta node is a way to pass information about a method to the compiler.

--Blake