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Re: AsyncWork<Vector<T>> fails due to lack of copy-constructor [message #52896 is a reply to message #52895]

Tue, 07 January 2020 00:14

piotr5
Messages: 107
Registered: November 2005

Experienced Member

In file included from /home/p/upp/uppsrc/Core/Core.h:342,
                 from /home/p/upp/uppsrc/Draw/Draw.h:6,
                 from /home/p/upp/uppsrc/RichText/RichText.h:4,
                 from /home/p/upp/uppsrc/CtrlCore/CtrlCore.h:4,
                 from /home/p/upp/uppsrc/CtrlLib/CtrlLib.h:4,
                 from /home/p/MyApps/arrow2circle/arrow2circle.h:4,
                 from /home/p/MyApps/arrow2circle/main.cpp:1:
/home/p/upp/uppsrc/Core/CoWork.h: In instantiation of 'Ret2 Upp::AsyncWork<Ret>::Imp<Ret2>::Get() [with Ret2 = Upp::Vector<unsigned char>; Ret = Upp::Vector<unsigned char>]':
/home/p/upp/uppsrc/Core/CoWork.h:195:99:   required from 'Ret Upp::AsyncWork<Ret>::Get() [with Ret = Upp::Vector<unsigned char>]'
/home/p/MyApps/arrow2circle/arrow2circle.h:28:18:   required from here
/home/p/upp/uppsrc/Core/CoWork.h:173:50: error: use of deleted function 'constexpr Upp::Vector<unsigned char>::Vector(const Upp::Vector<unsigned char>&)'
  173 |   Ret2 Get()                            { return ret; }
      |                                                  ^~~

similar if I add "pick(ret)" in place of "ret"

/home/p/upp/uppsrc/Core/CoWork.h: In instantiation of 'Ret2& Upp::AsyncWork<Ret>::Imp<Ret2>::Get() [with Ret2 = Upp::Vector<unsigned char>; Ret = Upp::Vector<unsigned char>]':
/home/p/upp/uppsrc/Core/CoWork.h:195:99:   required from 'Ret Upp::AsyncWork<Ret>::Get() [with Ret = Upp::Vector<unsigned char>]'
/home/p/MyApps/arrow2circle/arrow2circle.h:28:18:   required from here
/home/p/upp/uppsrc/Core/CoWork.h:173:59: error: cannot bind non-const lvalue reference of type 'Upp::Vector<unsigned char>&' to an rvalue of type 'std::remove_reference<Upp::Vector<unsigned char>&>::type' {aka 'U
    pp::Vector<unsigned char>'}

my code is just simple file-processing, here a short version:

#include <Core/Core.h>
#include <array>
using namespace Upp;

struct Parse {
	using CLASSNAME=Parse;
	std::array<AsyncWork<Vector<byte> >,3 > parser;
	FindFile path;
	
	void init(const String& p) {path.Search(p); for(auto&& i:parser) {i.Cancel();SetWork(i);};}
	Vector<byte> Work(const String& file);
	void SetWork(AsyncWork<Vector<byte> >& where) {if(path&&path.IsFile()&&path.GetLength()>0) {
		where.Do(THISFN(Work),path.GetPath());
		path.Next();
	};}
	void AddWork() { for(auto&& i:parser) if(i.IsFinished()) {
		auto out=i.Get();
		SetWork(i);
	}}
};

Vector<byte> Parse::Work(const String& file) {
	Vector<byte> out;
	return out;
}
CONSOLE_APP_MAIN
{
	Parse p;
	p.init(CommandLine()[1]);
}

this works with

		Ret Get()                            { return pick(ret); }

and also if I put "Ret&&" in place of "Ret" and use pick as above. using "std::forward<Ret2>(ret)" is a better idea here? (I compile with "-std=gnu++1z" and gcc-9.2.0)

Oh, and thanks for the hint. I'll try using CoWork to see if it's any better than my boilerplate...

[Updated on: Tue, 07 January 2020 00:41]

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