Cstring as ccall return value

[maleadt]

Does it make sense to use Cstring as the return value type when ccall'ing methods returning a char* string? I know the type is mainly intended to avoid converting Julia strings containing \0 to C strings, but I thought it would also make sense to use it as the ccall return type because it makes the code more readable (i.e. "this code returns a string" rather than "it's just a pointer").

However, I'm afraid there might be a gotcha:

julia> Ptr{UInt8}(0x0) == C_NULL
true

julia> Cstring(Ptr{UInt8}(0x0)) == C_NULL
false

Is this intended? Some API's (for example tempnam) return NULL upon failure, so that would break when using Cstring as ccall's return value type and subsequently comparing against C_NULL.

[Stefan Karpinski]

That comparison should really either return true or fail. Could you open an issue?

[maleadt]

Done, see issue #13974.

Op vrijdag 13 november 2015 15:37:10 UTC+1 schreef Stefan Karpinski: