March 11, 2011 Why is the struct instance being copied here? | ||||
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| Greetings Please look at the code down here. When compiled and run, I get the message "Call to postblit" printed. I think it is because of the foreach block, because the variable "i" is not declared as ref there. Is there a way to make it a ref? Regards - Puneet import std.stdio; struct Foo { this(this) { writeln("Call to postblit"); } } class Bar { Foo foo; this() { foreach(i, f; this.tupleof) { // do nothing } } } void main() { Bar bar = new Bar(); } |
March 11, 2011 Re: Why is the struct instance being copied here? | ||||
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Posted in reply to d coder | On Fri, 11 Mar 2011 04:50:38 -0500, d coder <dlang.coder@gmail.com> wrote: > Greetings > > Please look at the code down here. When compiled and run, I get the message > "Call to postblit" printed. I think it is because of the foreach block, > because the variable "i" is not declared as ref there. Is there a way to > make it a ref? > > Regards > - Puneet > > import std.stdio; > > struct Foo { > this(this) { > writeln("Call to postblit"); > } > } > > class Bar { > Foo foo; > this() { > foreach(i, f; this.tupleof) { > // do nothing > } > } > } > > void main() > { > Bar bar = new Bar(); > } This typically works in a foreach loop: foreach(i, ref f; x) but a foreach for a tuple is a special beast, and using ref in your code yields this error: foreachtuple.d(12): Error: no storage class for value f But I agree it should be doable. This should qualify for an enhancement request: http://d.puremagic.com/issues/enter_bug.cgi?product=D -Steve |
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