Am Fri, 23 Aug 2013 09:46:13 +0200 schrieb Johannes Pfau <nos...@example.com>:
> Am Wed, 07 Aug 2013 00:05:35 +0200 > schrieb "Timofei Bolshakov" <tbo...@gmail.com>: > > > Hello! > > > > I got strange problem. > > When I am trying to send a message containing a struct of size 30 > > I am getting a strange exception: > > > > core.exception.AssertError@/home/tbolshakov/x-tools/arm-unknown-linux-gnueabi-gdc/lib/gcc/arm-unknown-linux-gnueabi/4.7.2/include/d/std/variant.d(280): > > > > target must be non-null > > > > The code looks like: > > // enum ove the byte string string > > uint ushort struct > > send( tid, MessageTag.SPTRecord, gwmac_str, > > mac2HexString(t[0].idup), utc, ms, aStruct ); > > > > Does anybody have an idea why? Does anybody have an idea hw to > > fix it? > > > > I have DGC version 2.0.59 made with gcc 4.7.2 (crosstool-ng > > 1.18.0). > > There are bugs in std.variant on ARM. > > But in this case it might have a different cause: std.concurrency > stores data in a Variant (see std.variant). A variant can only store > things with a maximum size of creal.sizeof. On x86 creal is a pair of > 2 reals, so 12/16bytes + alignment = 32 bytes. > > On ARM real == double = 8 bytes, so creal.sizeof is 16 bytes. So the > max size of a struct which can be stored in a Variant is 16 on ARM. > This is basically a problem in Variant's design, it's not really meant > to support struct types. It's for basic types only. This is why > VariantN exists where you can define your own max size. But you can't > access that functionality through std.concurrency. > > I'd say file a bug report on std.concurrency that big structs are not > supported and mention the issue that on non-x86 the max size is 16 > byte only. http://d.puremagic.com/issues/show_bug.cgi?id=10740
