__traits(compiles , mixin ... )
Adam D. Ruppe
destructionator at gmail.com
Wed Oct 25 20:04:47 UTC 2017
On Wednesday, 25 October 2017 at 19:50:31 UTC, SrMordred wrote:
> so why this line resolves to false?
Because it is illegal to put a statement or declaration inside
__traits(compiles). sorry, I should have said that before... even
though the mixin can be legal in another context, it won't be in
the __traits context due to this:
https://dlang.org/spec/traits.html#compiles
"Returns a bool true if all of the arguments compile (are
semantically correct). The arguments can be symbols, types, or
expressions that are syntactically correct. The arguments cannot
be statements or declarations. "
When there's a closing ;, it is a mixin statement.
> void F(){}
> pragma(msg, __traits( compiles, mixin("F();") ) );//false
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